Cystic-multilocular variant; Grawitz tumor is a type of kidney cancer that forms many fluid-filled spaces (cysts) separated by thin walls inside the kidney. It belongs to the clear cell renal cell carcinoma (RCC) family, which is the most common kidney cancer in adults.
Cystic-multilocular variant of Grawitz tumour refers to a rare form of clear-cell renal cell carcinoma (RCC) where the kidney cancer grows mainly as many fluid-filled cysts separated by thin walls, instead of a solid mass. Doctors now call many of these lesions “multilocular cystic renal neoplasm of low malignant potential,” because the cancer cells are low-grade and the risk of spread is usually very low.
Like other Grawitz tumours, this variant arises from the cells lining the kidney tubules, but its cystic nature often makes it look less aggressive on imaging, and most patients do very well after surgery. However, once the disease behaves like typical clear-cell RCC (large mass, invasion, or metastasis), doctors follow the same evidence-based treatment plans used for other advanced RCC types, including surgery, targeted drugs and immunotherapy.
In modern names, this cystic-multilocular form is usually called multilocular cystic renal neoplasm of low malignant potential (MCRNLMP) or multilocular cystic renal cell carcinoma. It is made almost completely of cysts, with cancer-type clear cells only lining the thin walls, and it has a very good, almost benign-like prognosis after surgery.
The word “Grawitz tumour” is an old term for clear cell RCC. Today doctors prefer “renal cell carcinoma” or “clear cell renal cell carcinoma,” but many older books still use “Grawitz tumour,” so you may see both names for the same basic disease group.
Other names
Doctors and books may use several names for this tumour. All of the names below refer to either clear cell RCC in general or its multilocular cystic variant, depending on context:
Grawitz tumour
Hypernephroma (old term)
Clear cell renal cell carcinoma
Clear cell adenocarcinoma of kidney
Renal cell carcinoma (clear cell type)
Multilocular cystic renal cell carcinoma
Multilocular cystic renal neoplasm of low malignant potential (MCRNLMP)
Multicystic clear cell carcinoma of kidney
Types
Clear cell RCC (Grawitz tumour) can be grouped into types or patterns. The cystic-multilocular variant is one of these patterns.
Typical solid clear cell RCC – The tumour is mostly solid, made of clear cells that grow as nests or sheets, often with rich blood supply and sometimes areas of necrosis (dead tissue).
Multilocular cystic renal neoplasm of low malignant potential (MCRNLMP) – The tumour is made almost entirely of many cysts, with small clusters or linings of clear cells in the walls. It behaves in a very gentle way and almost never spreads when completely removed.
Clear cell RCC with cystic degeneration – A usual clear cell tumour that later forms cystic spaces due to breakdown and fluid collection inside; this form does not have the same very good prognosis as true multilocular cystic neoplasm.
Hereditary clear cell RCC in syndromes (for example von Hippel–Lindau disease) – Clear cell tumours that occur in families with specific gene changes; they may be multiple and appear at younger age.
Other non-clear cell RCC subtypes for comparison – Papillary, chromophobe, collecting duct and other rare types are not Grawitz tumours, but doctors must tell them apart because behaviour and treatment can differ.
Causes (risk factors)
In most people, doctors cannot find one single cause for a cystic-multilocular Grawitz tumour. Instead we talk about risk factors, which are things that increase the chance of developing clear cell RCC.
Cigarette smoking – Smoking is one of the strongest and best-proven risk factors for RCC. Chemicals in tobacco smoke are filtered through the kidneys and may damage kidney cell DNA over time, making cancerous change more likely.
Obesity – Extra body fat changes hormone and growth factor levels, and can cause chronic low-grade inflammation. These changes may stimulate abnormal growth in kidney tubule cells and increase the risk of clear cell RCC, including cystic variants.
High blood pressure (hypertension) – Long-term high blood pressure damages small kidney blood vessels and tubules. This ongoing stress and repair can make DNA errors more common and raise the chance of RCC development.
Certain blood pressure medicines (possible association) – Some observational studies suggest that long-term use of particular antihypertensive drugs might be linked to a slightly higher RCC risk, but this link is not completely clear and may relate more to the hypertension itself.
Chronic kidney disease – People with long-standing kidney failure, especially those on dialysis, have a higher rate of renal tumours, including cystic types. Damaged kidneys show scarring, chronic inflammation and cyst formation, which together favour tumour growth.
Acquired cystic kidney disease – Patients on long-term dialysis often develop many kidney cysts. Cancer can arise in the wall of these cysts, and a tumour with multilocular (many-cyst) appearance may be seen.
Family history of RCC – Having a close relative with RCC roughly doubles the risk. Shared genes and sometimes shared lifestyle factors can both contribute to this increased chance.
Von Hippel–Lindau (VHL) disease – This inherited gene disorder strongly increases risk for clear cell RCC and multiple renal cysts. Loss of VHL gene function leads to over-active growth signals and new blood vessel formation in kidney cells.
Other hereditary RCC syndromes – Conditions such as Birt–Hogg–Dubé syndrome or hereditary leiomyomatosis and RCC carry increased RCC risk. In these disorders, germline mutations in tumour-suppressor genes make kidney cells more likely to become malignant.
Occupational exposure to certain chemicals – Long-term exposure to trichloroethylene, some heavy metals, and some industrial solvents has been linked with higher RCC risk, probably due to direct DNA damage in kidney tubule cells.
Long-term use of some painkillers – Long-term, heavy use of certain analgesics, especially older phenacetin-containing drugs, has been associated with kidney damage and a higher risk of kidney tumours.
Male sex – Men develop RCC about twice as often as women. Hormone differences, different smoking rates and different workplace exposures may all play a part in this sex-linked risk.
Older age – RCC is mainly a disease of middle-aged and older adults. Over time, kidney cells collect more DNA damage from normal life and from environmental exposures, making cancer more likely with increasing age.
Diabetes mellitus – Some studies suggest that people with long-standing diabetes may have a higher RCC risk, possibly due to insulin resistance, chronic inflammation, and vascular damage in kidney tissue.
Metabolic syndrome – A combination of obesity, high blood pressure, abnormal lipids and insulin resistance has been linked to kidney cancer. Together these factors produce hormonal and inflammatory changes that may drive tumour growth.
Long-term immunosuppression – Patients after organ transplantation or with chronic immune-suppressing treatment have a higher risk of many cancers, including RCC, because their immune system is less able to remove early abnormal cells.
Previous radiation to the abdomen – Rarely, high-dose radiation given for other cancers in the abdominal area can damage kidney DNA and slightly increase later RCC risk.
Chronic kidney infections and inflammation – Long-standing infections or inflammatory conditions of the kidney may create a setting of repeated injury and repair, which can allow cancer-causing DNA changes to build up.
Unhealthy diet and low physical activity – Diets high in processed meat, high salt and low in fruits and vegetables, together with lack of exercise, contribute to obesity and metabolic changes that indirectly increase RCC risk.
Unknown or random genetic events – In many patients no clear risk factor is found. Random DNA errors during cell division in kidney tubules may sometimes be enough to start tumour growth, including cystic-multilocular variants.
Symptoms
The multilocular cystic variant often grows slowly and may be found by chance. Many patients have no symptoms at first, especially when tumours are small.
No symptoms (incidental finding) – Many lesions are discovered during ultrasound, CT or MRI done for other reasons. The patient feels well, and the tumour is a surprise on imaging.
Flank or side pain – Dull, aching pain in the side or back below the ribs can occur when the cystic mass stretches the kidney capsule or presses on nearby tissues.
Abdominal or flank lump – Sometimes a doctor or the patient can feel a firm or cystic mass in the upper abdomen or flank. This is more common when the tumour is large.
Blood in the urine (haematuria) – The urine may become pink, red or cola-coloured when fragile tumour blood vessels bleed into the collecting system. Sometimes blood is only visible under the microscope.
Frequent or painful urination – If the mass irritates the urinary tract or causes small clots, the patient can feel burning, urgency or the need to pass urine more often.
Unexplained weight loss – Some patients lose weight without trying. Tumour-released substances and increased body energy use can cause this cancer-related weight loss.
Fever without clear infection – Ongoing low-grade fever can occur because the tumour releases inflammatory chemicals called cytokines, even when there is no infection.
Tiredness and weakness (fatigue) – Chronic inflammation, mild anaemia and disturbed metabolism can make patients feel unusually tired, even after enough rest and sleep.
Loss of appetite – Many people with RCC feel less hungry or feel full quickly. This is often related to tumour-driven changes in hormones and inflammatory signals.
High blood pressure or new-worsening hypertension – The tumour or damaged kidney may produce extra renin and other substances, raising blood pressure or making it harder to control.
Swelling of legs or ankles (oedema) – If the kidney function is affected or veins are compressed, fluid may build up in the legs or feet, causing puffy swelling.
Varicocele in men (especially on the right side or sudden onset) – A kidney mass can press on veins draining the testicle, causing enlarged, twisted veins like a “bag of worms” in the scrotum.
Anaemia (low haemoglobin) – Chronic blood loss into urine, inflammation and kidney dysfunction can lower red blood cell levels, leading to pallor, fatigue and shortness of breath on effort.
Polycythaemia (high red cell count) in some cases – Paradoxically, some RCCs make extra erythropoietin, a hormone that boosts red cell production, causing raised haemoglobin and thickened blood.
Bone pain, cough or shortness of breath (advanced disease) – These symptoms usually suggest spread to bone or lungs and are much less common in true multilocular cystic neoplasms, which very rarely metastasize.
Diagnostic tests –
Physical examination
In cystic-multilocular Grawitz tumours, the physical exam may be normal if the tumour is small, but doctors still look for important signs.
General inspection and vital signs – The doctor checks weight, temperature, pulse and blood pressure. Fever, weight loss, or high blood pressure can all point toward a possible renal cancer or its systemic effects.
Abdominal and flank palpation – The doctor gently feels the abdomen and flanks for any lump, tenderness or mass. A large cystic-multilocular tumour may feel like a smooth or irregular swelling in the upper abdomen or side.
Examination for leg swelling and varicocele – The doctor looks for ankle oedema and, in men, dilated scrotal veins. These findings may suggest impaired kidney function or compression of major veins by a renal mass.
Lymph node examination – Enlarged lymph nodes in the neck, armpits or groin are checked, though they are less typical in early cystic variants. Large nodes may indicate spread or another condition needing investigation.
Diagnostic tests – Manual tests
Manual bedside tests are simple bedside manoeuvres using hands or basic tools to look for kidney-related signs.
Costovertebral angle (CVA) tenderness test – The doctor gently taps over the angle between the lower ribs and backbone. Tenderness here suggests kidney irritation or stretching by a mass or infection on that side.
Abdominal percussion and ballottement – By tapping and pushing the flank while feeling from the front, the doctor can sense a floating mass, which may represent an enlarged kidney or cystic tumour.
Pitting oedema assessment – Pressing a thumb over the shin or ankle for several seconds can show pitting oedema if a dent remains. This manual test helps judge fluid overload that may accompany kidney disease.
Diagnostic tests – Lab and pathological tests
Laboratory and tissue tests help confirm diagnosis, assess kidney function and stage the disease.
Urinalysis – A simple urine test can show blood, protein or abnormal cells. Microscopic haematuria (blood cells in urine) is common in kidney tumours, even when urine looks normal to the eye.
Complete blood count (CBC) – This test checks haemoglobin, white cells and platelets. It can detect anaemia, inflammation or rarely polycythaemia in RCC patients.
Serum creatinine and estimated GFR – These blood tests measure kidney function. They are crucial before imaging with contrast and before surgery, and they help plan nephron-sparing versus radical nephrectomy.
Liver function tests and alkaline phosphatase – Abnormal values may suggest liver involvement or bone disease, which can occur in advanced RCC, though this is rare in pure multilocular cystic tumours.
Serum calcium – High calcium levels can result from tumour-produced hormones or bone metastases. Monitoring calcium helps detect these paraneoplastic effects early.
Coagulation profile – Tests like PT and aPTT are checked before biopsy or surgery. Some RCC patients have clotting abnormalities or are at higher risk of blood clots.
Histopathology of the tumour (gold standard) – After partial or radical nephrectomy, a pathologist examines the tumour under the microscope. For cystic-multilocular variants, they see many cysts with thin fibrous walls lined by low-grade clear cells and no solid expansile nodules, which defines MCRNLMP.
Immunohistochemistry and molecular tests – Special stains and genetic tests can confirm clear cell phenotype and 3p/VHL pathway changes, and help distinguish MCRNLMP from other cystic kidney lesions.
Diagnostic tests – Electrodiagnostic tests
Electrodiagnostic tests are not used to diagnose the kidney tumour itself, but they are helpful in pre-operative evaluation and in looking for complications.
Electrocardiogram (ECG) – An ECG records heart rhythm and conduction. It is important before anaesthesia, especially in older or high-risk RCC patients, and in those with high blood pressure or electrolyte problems from kidney disease.
Electromyography (EMG) and nerve conduction studies (if needed) – In rare cases, RCC is linked to paraneoplastic neuropathies. EMG and nerve tests can look for nerve damage if patients have unexplained weakness, numbness or muscle cramps.
Electroencephalogram (EEG) (selected cases) – If a patient with advanced RCC develops seizures or confusion, EEG can help assess brain function along with imaging to look for brain metastases or metabolic causes.
Diagnostic tests – Imaging tests
Imaging is central for detecting, characterising and staging cystic-multilocular Grawitz tumours. The multilocular cystic appearance is best seen on modern scans.
Renal ultrasound – This is often the first imaging test. It uses sound waves to show kidney shape and internal structure. A multilocular cystic tumour appears as a complex mass with many fluid spaces and internal walls.
Contrast-enhanced CT scan of abdomen – CT with contrast is the main imaging tool. It can show the many cysts, thin enhancing septa and absence of solid nodules that suggest MCRNLMP rather than typical solid RCC. CT also checks nearby organs and lymph nodes.
MRI of kidneys – MRI helps when CT findings are unclear or when contrast CT is unsafe. It gives excellent soft-tissue contrast and can better show septal enhancement, haemorrhage and relation to blood vessels, aiding surgical planning.
Chest CT or X-ray – These images check for lung spread or other chest involvement in RCC. Metastasis is extremely uncommon in pure multilocular cystic neoplasm, but staging is still done to be safe.
Bone scan or PET-CT (selected cases) – These advanced scans are used when symptoms or lab findings suggest bone or widespread disease. They are usually not needed for typical low-grade multilocular cystic neoplasms with excellent prognosis.
Non-pharmacological treatments (therapies and other approaches)
1. Careful imaging, staging and risk assessment
The first non-drug “treatment” is precise diagnosis. Doctors use ultrasound, CT, or MRI to confirm a multilocular cystic tumour, check both kidneys, and look for spread to veins, lymph nodes, lungs, liver or bones. They also classify risk using size, stage and lab tests. Good staging helps avoid overtreatment in low-risk lesions and ensures timely therapy in advanced disease.
2. Active surveillance for very small, low-risk lesions
In older or frail patients with tiny, slow-growing cystic tumours, doctors may suggest active surveillance instead of immediate surgery. This means regular imaging and clinical review to track growth and symptoms. The purpose is to avoid surgical risks if the tumour is unlikely to cause trouble. The mechanism is simple: treat only if the cancer shows clear signs of progression.
3. Partial nephrectomy (nephron-sparing, as a conservative option)
Although technically a surgery, partial nephrectomy is also a kidney-preserving strategy. When feasible, surgeons remove just the tumour and a small rim of normal tissue, keeping the rest of the kidney working. The purpose is to cure the cancer while protecting long-term kidney function. It works by physically excising all visible tumour while preserving as much healthy nephrons as possible.
4. Image-guided ablation (cryoablation or radiofrequency ablation)
For selected small renal tumours in patients unfit for surgery, interventional radiologists can destroy the lesion using needles guided by CT or ultrasound. Cryoablation freezes the tumour; radiofrequency ablation heats and coagulates it. The goal is local control with minimal blood loss and short hospital stay. The mechanism is thermal injury that kills cancer cells while sparing most surrounding tissue.
5. Stereotactic body radiotherapy (SBRT) for inoperable cases
Radiotherapy is not a primary treatment for typical RCC, but modern stereotactic body radiotherapy can be used for inoperable kidney tumours or painful metastases. Very focused, high-dose beams are delivered over a few sessions. The aim is to shrink or stabilise lesions and relieve pain. The mechanism is DNA damage in cancer cells, leading to loss of their ability to divide.
6. Palliative external-beam radiotherapy for bone pain
When metastatic Grawitz tumours reach bone, they can cause severe pain or risk of fracture. A short course of palliative radiotherapy (often 1–10 sessions) is a non-drug way to reduce pain and strengthen the affected area. It works by damaging tumour cells in bone, reducing local inflammation and pressure on nearby nerves.
7. Structured pain-management programmes
Non-pharmacological pain-management programmes include physiotherapy, heat or cold packs, relaxation techniques, breathing exercises, and cognitive-behavioural therapy alongside medicines. The purpose is to improve function and quality of life, not just reduce pain scores. These approaches work by calming the nervous system, improving muscle balance, and changing how the brain interprets pain signals.
8. Exercise and physical-activity rehabilitation
Tailored exercise programmes help keep muscles strong, support heart and lung health, reduce fatigue, and improve mood during and after cancer treatment. Simple walking, light resistance training and stretching are usually recommended. The mechanism involves better blood flow, anti-inflammatory effects, and improved insulin sensitivity, which together support overall resilience.
9. Nutritional counselling and kidney-friendly diet
Dietitians help people with kidney cancer choose foods that support healing while protecting kidney function – for example, emphasising fruits, vegetables, whole grains and appropriate protein, while limiting salt and processed foods. The goal is to maintain strength and healthy weight. Mechanistically, good nutrition supports immune cells, wound healing, and stable blood pressure and blood sugar.
10. Fluid- and blood-pressure management
Controlling blood pressure and staying appropriately hydrated protects the remaining kidney tissue, especially if one kidney has been removed. Lifestyle steps include reduced salt intake, weight control, and regular monitoring. The mechanism is reduced pressure on glomeruli and better long-term kidney filtration, lowering the risk of chronic kidney disease.
11. Smoking-cessation support
Smoking increases the risk of kidney cancer and worsens outcomes in people already diagnosed. Counselling, support groups, and nicotine-replacement therapies can be combined to help patients quit. Stopping smoking reduces toxic exposures, improves oxygen delivery, and lowers the risk of new cancers and cardiovascular disease, which is especially important after nephrectomy.
12. Weight management and metabolic-syndrome control
Extra body weight, diabetes and high cholesterol all increase kidney-cancer risk and strain the kidneys. A structured programme of diet, activity and sometimes bariatric referral helps gradually reach safer weight. Mechanistically, this lowers inflammatory hormones, improves insulin sensitivity and reduces blood-pressure load, which together support better survival and kidney function.
13. Psycho-oncology and counselling
A cancer diagnosis often brings anxiety, low mood and fear of recurrence. Psycho-oncology services provide counselling or group therapy tailored to people with cancer. These programmes aim to improve coping skills, sleep, adherence to treatment and overall quality of life. They work by giving emotional support, practical strategies, and a safe space to talk about worries.
14. Palliative-care and symptom-control services
Palliative-care teams focus on relief of symptoms such as pain, breathlessness, nausea, fatigue and emotional distress at any stage of disease – not only end-of-life. The purpose is to live as well as possible with cancer. Their mechanisms include early symptom assessment, coordinated care, and honest communication about goals and preferences.
15. Occupational therapy and daily-life adaptations
Occupational therapists help patients adjust their home and work tasks to match their energy levels and physical abilities. This may include pacing techniques, assistive devices, and home safety changes. The mechanism is practical: reduce strain, prevent falls and conserve energy, so people can remain independent longer.
16. Structured follow-up and survivorship clinics
After surgery or systemic therapy, regular follow-up with labs and imaging is essential. Survivorship clinics provide standardised schedules and education on late effects, recurrence risk and lifestyle. The mechanism is early detection of relapse or new problems, allowing earlier, more effective intervention.
17. Education on nephrotoxic-drug avoidance
Patients are educated to avoid or minimise medicines that can harm kidneys, such as long-term high-dose NSAIDs or certain contrast dyes, unless clearly needed. The purpose is to protect kidney function, especially when one kidney has been removed. Mechanistically, this prevents further injury to glomeruli and tubules already under stress.
18. Infection-prevention measures
Good hand hygiene, up-to-date vaccines, dental care and care with catheter use all lower infection risk, which is particularly important for people receiving immunotherapy or targeted drugs. The mechanism is simple: fewer pathogens reach the body, and the immune system is not distracted from fighting cancer.
19. Stress-reduction and mind–body techniques
Practices such as mindfulness, meditation, yoga, or gentle breathing exercises can lower perceived stress, improve sleep and reduce pain intensity. They act through neuro-hormonal pathways, lowering cortisol and sympathetic-nervous-system activation, which can otherwise worsen fatigue and blood-pressure control in kidney-cancer patients.
20. Social-work and financial-counselling support
Cancer care can be expensive and logistically challenging. Social workers help patients access insurance benefits, sick leave, transport, and other support. This non-medical intervention indirectly improves outcomes by reducing treatment delays, encouraging adherence and easing emotional and financial stress on families.
Drug treatments
Very important: Drug choices, combinations and doses must always be decided by a specialist oncology team. The following is general educational information only, based on FDA labels and major guidelines for advanced or high-risk RCC, not personal medical advice.
1. Pembrolizumab + axitinib
Pembrolizumab is an immune checkpoint inhibitor (anti-PD-1 antibody) and axitinib is an oral VEGF-receptor tyrosine-kinase inhibitor (TKI). Together they are an established first-line treatment for advanced clear-cell RCC. A common regimen is pembrolizumab IV every 3 or 6 weeks plus axitinib tablets twice daily, adjusted for side effects. This combination works by boosting T-cell attack on tumour cells while blocking tumour blood-vessel growth; main risks include immune-related inflammation, hypertension and liver issues.
2. Pembrolizumab + lenvatinib
Pembrolizumab can also be combined with lenvatinib, another multi-target VEGF-pathway TKI. This regimen is used first-line for advanced RCC and in some high-risk post-surgery situations. Lenvatinib tablets are usually taken once daily with pembrolizumab infusions on a regular schedule. The pair improves progression-free survival by simultaneously activating immune responses and suppressing angiogenesis. Common side effects include diarrhoea, high blood pressure, protein in urine and fatigue.
3. Nivolumab + ipilimumab
Nivolumab (PD-1 inhibitor) plus ipilimumab (CTLA-4 inhibitor) is a powerful immune-checkpoint combination for previously untreated advanced RCC, especially in intermediate- or poor-risk patients. Treatment begins with several combination cycles IV, followed by nivolumab maintenance alone. The purpose is deep, durable immune activation against the tumour; however, the mechanism also increases the risk of severe immune-related side effects such as colitis, hepatitis or endocrinopathies that require close monitoring and steroid treatment.
4. Nivolumab monotherapy
Nivolumab alone is approved for patients with RCC whose cancer has already been treated with anti-angiogenic therapy and then progressed. It is given as regular IV infusions. The drug blocks PD-1 on T cells, removing a “brake” and allowing the immune system to recognise and attack cancer cells more effectively. Key side effects include fatigue, rash, diarrhoea and immune-mediated organ inflammation that must be detected early.
5. Nivolumab + cabozantinib
This combination pairs immune checkpoint blockade (nivolumab) with a potent multi-kinase inhibitor (cabozantinib) as a first-line option for advanced RCC. Cabozantinib targets VEGF receptors and other kinases like MET and AXL, which are involved in tumour growth and resistance. Typical regimens use daily oral cabozantinib plus IV nivolumab on a fixed schedule. Side effects include diarrhoea, high blood pressure, hand–foot syndrome and immune toxicities, so doses are frequently adjusted.
6. Cabozantinib (single-agent)
Cabozantinib is an oral TKI used after prior anti-angiogenic therapy and also as first-line in some settings. A common starting dose is 60 mg once daily, taken on an empty stomach and continued until progression or intolerable toxicity, according to the FDA label. The drug works by blocking VEGF, MET and AXL signalling, inhibiting tumour blood-vessel formation and growth. Typical side effects are diarrhoea, mucositis, hypertension, fatigue and risk of bleeding or clotting.
7. Sunitinib
Sunitinib is a well-known first-line or later-line VEGF-pathway TKI for RCC. It is usually taken orally once daily in cycles (for example, 4 weeks on, 2 weeks off), with dose changes based on tolerance. Sunitinib blocks multiple receptor kinases involved in angiogenesis and tumour proliferation. Common adverse effects include fatigue, hand–foot skin reaction, high blood pressure, thyroid dysfunction and low blood counts, so regular blood tests and blood-pressure monitoring are required.
8. Pazopanib
Pazopanib is another oral VEGF-pathway TKI that can be used for advanced RCC, often in patients who cannot tolerate sunitinib. It is usually taken once daily with food restrictions. The drug targets VEGF, PDGF and related pathways to reduce tumour blood supply. Key side effects include liver-enzyme elevation, diarrhoea, hair colour changes, hypertension and fatigue, so liver tests and blood pressure should be checked regularly.
9. Lenvatinib + everolimus
For patients who have already received one VEGF-targeted therapy, lenvatinib combined with everolimus (an mTOR inhibitor) is an option. Lenvatinib tablets are taken daily at a lower dose when combined, and everolimus is also taken orally daily. This dual approach blocks both angiogenesis and mTOR-driven cell growth. Side effects include diarrhoea, mouth sores, infections, high blood pressure and metabolic changes, so careful monitoring is essential.
10. Everolimus (single-agent)
Everolimus alone is used for some patients who have progressed after VEGF-TKI therapy. It is an oral mTOR-pathway inhibitor given once daily. By blocking mTOR, it slows cell growth and metabolism in cancer cells. Common side effects are mouth ulcers, rash, high blood sugar and high cholesterol, as well as increased infection risk due to immune suppression, so blood tests and oral care are important.
11. Temsirolimus
Temsirolimus is an IV mTOR inhibitor mostly used for poor-risk advanced RCC. It is usually infused weekly. Its mechanism is similar to everolimus, targeting the mTOR complex to slow cell growth and angiogenesis. It can cause rash, mouth sores, elevated lipids, anaemia and higher infection risk, and may be chosen when rapid systemic therapy is required in very high-risk disease.
12. Sorafenib
Sorafenib, another multi-kinase inhibitor, is less commonly used now but remains a later-line option in some settings. It is taken orally twice daily and blocks several pathways including RAF kinases and VEGF receptors. It may slow tumour growth but often causes hand–foot skin reaction, diarrhoea, fatigue and high blood pressure, so it is usually reserved when other TKIs and immunotherapies are not suitable.
13. Avelumab + axitinib
Avelumab (a PD-L1 inhibitor) combined with axitinib is another immunotherapy–TKI pair approved for first-line treatment of advanced RCC. Avelumab is given IV every 2 weeks while axitinib is taken orally twice daily. The purpose and mechanism are similar to other ICI + TKI combinations: enhance immune attack and starve the tumour of blood supply. Side effects include infusion reactions, immune-related events, and TKI-type toxicities.
14. Belzutifan (Welireg)
Belzutifan is a hypoxia-inducible factor-2α (HIF-2α) inhibitor, now approved for advanced RCC with a clear-cell component after prior PD-1/PD-L1 inhibitor and VEGF-TKI therapy, and for VHL-associated RCC. It is taken orally once daily. By blocking HIF-2α, belzutifan interferes with tumour adaptation to low-oxygen conditions and reduces expression of genes driving growth and angiogenesis. Main risks include anaemia, hypoxia and embryo-foetal toxicity, so close monitoring is required.
(Other systemic options such as bevacizumab with interferon, high-dose interleukin-2, and chemotherapy are now used much less frequently and mainly in specialised centres or clinical trials.)
Dietary molecular supplements
These supplements are not proven cures for cystic-multilocular Grawitz tumours. They are general supportive ideas sometimes discussed in cancer nutrition. Always ask your oncology team before starting any supplement, as some can interact with kidney-cancer drugs or strain the kidneys.
Vitamin D – Many people with cancer have low vitamin D. Typical supplements range from 600–2000 IU per day, adjusted by blood levels. Vitamin D helps regulate bone health, immune function and cell growth. Mechanistically it binds nuclear receptors that can influence cell-cycle control and inflammation. In kidney-cancer patients, dosing must be individualised because of altered kidney activation of vitamin D.
Omega-3 fatty acids (fish-oil or algae-oil) – Omega-3s (EPA/DHA) in doses around 1–2 g/day are sometimes used to help with inflammation, weight maintenance and cardiovascular risk. They act by being built into cell membranes and shifting production of signalling molecules toward less inflammatory types. People on blood thinners or with bleeding risks should only use them under supervision.
Probiotics – Selected probiotic strains may support gut health during targeted therapy or immunotherapy by improving stool regularity and helping the microbiome recover after antibiotics. Doses vary by product. Mechanistically, they compete with harmful bacteria and modulate immune responses in the gut. However, in severely immunocompromised patients probiotics should be used cautiously.
Curcumin (turmeric extract) – Curcumin has anti-inflammatory and antioxidant effects in lab studies. Typical oral supplements are 500–1000 mg/day of standardised extract, often with piperine to improve absorption. It influences NF-κB and other signalling pathways. Because it can affect liver enzymes and blood clotting, people on TKIs or anticoagulants must ask their doctor first.
Green-tea extract (EGCG) – Green-tea polyphenols show anti-oxidant and anti-proliferative effects in experimental studies, but high-dose extracts have occasionally caused liver injury. If used, low-to-moderate doses and liver-function monitoring are important. Mechanism involves scavenging free radicals and altering signalling pathways linked to cell growth and angiogenesis.
Selenium (within recommended limits) – Selenium is an essential trace mineral with roles in antioxidant enzymes. Supplements usually stay within 50–200 µg/day to avoid toxicity. It supports glutathione peroxidase activity, which helps control oxidative stress. Excess intake can damage hair, nails and nerves, so guidance from a clinician is necessary, especially in kidney impairment.
Vitamin C (moderate doses) – Vitamin C supports immune function and collagen synthesis. Oral doses of 200–500 mg/day are usually sufficient for most people. Very high doses may increase oxalate and stone risk, which is a concern in kidney disease. Its mechanism includes antioxidant activity and enzyme co-factor roles in many metabolic processes.
Magnesium (if deficient) – Cancer treatments, poor diet and diarrhoea can lower magnesium levels. Supplementing to normal range (often 200–400 mg/day in divided doses) supports muscle function, heart rhythm and glucose control. Mechanistically, magnesium is a co-factor for hundreds of enzymes. In kidney impairment, doses must be reduced to avoid high blood magnesium.
Coenzyme Q10 (CoQ10) – CoQ10 is involved in mitochondrial energy production and has antioxidant properties. Doses in supplements are often 100–200 mg/day. Some patients use it to help with fatigue, although strong cancer-specific evidence is limited. It may interact with blood-pressure and blood-thinning medicines, so oncology approval is essential.
Plant-based protein powders (kidney-adjusted) – When appetite is poor, kidney-friendly plant proteins (such as pea or rice blends) can help maintain muscle mass at modest doses prescribed by a dietitian. Mechanistically, they supply essential amino acids for tissue repair while limiting excess phosphorus and potassium compared with some animal proteins. Amounts must be tailored to kidney function and overall diet.
Immune-support, regenerative” and stem-cell-related approaches
At present, there are no approved stem-cell or regenerative drugs that cure multilocular cystic Grawitz tumours. The approaches below describe how the immune system and advanced research may support care; they are not simple “immunity-booster pills.”
Immune-checkpoint inhibitors (e.g., pembrolizumab, nivolumab, ipilimumab) – These drugs do not regenerate tissue but “re-educate” T cells to recognise cancer. By blocking PD-1 or CTLA-4, they release immune brakes so T cells can attack tumour cells more strongly. They are standard, evidence-based systemic therapies in advanced RCC and are already listed in the drug section.
Belzutifan and hypoxia-pathway targeting – Belzutifan interferes with HIF-2α, a key driver of tumour survival in low-oxygen environments. While not a “stem-cell drug,” it targets pathways that cancer stem-like cells rely on, and is approved for advanced RCC after prior therapies. Its role is disease control, not organ regeneration.
Hematopoietic growth factors (e.g., G-CSF, ESAs – supportive only) – Drugs like filgrastim or erythropoiesis-stimulating agents may be used to support blood counts in selected patients with treatment-related neutropenia or anaemia, under strict specialist guidance. They stimulate bone-marrow stem cells but do not treat the tumour itself, and they carry specific risks, so they are used cautiously.
Experimental cell-based immunotherapies (CAR-T, NK-cell therapies, dendritic-cell vaccines) – These are mostly in early-phase clinical trials for solid tumours, including RCC. They involve collecting immune cells, modifying or priming them in the lab, and reinfusing them to target cancer. At present, they are not standard treatment and should only be accessed through regulated clinical trials, not private “stem-cell clinics.”
Organ-protective strategies after nephrectomy – “Regeneration” after kidney surgery is mainly natural adaptive growth of the remaining kidney. Doctors support this with blood-pressure control, avoidance of nephrotoxic drugs, and lifestyle measures, rather than stem-cell medicines. The body’s own nephron remodelling is the key mechanism.
Clinical-trial participation – For some patients with advanced or relapsed disease, joining well-designed clinical trials of new immune or targeted therapies may offer access to cutting-edge options while helping science progress. Trials are carefully regulated, with strict safety monitoring, and represent the safest way to explore emerging “regenerative” concepts in RCC.
Surgical options
Partial nephrectomy – Removes only the cystic tumour and a margin of normal kidney, preserving as much healthy tissue as possible. It is often preferred for small, localised multilocular cystic lesions because these tumours usually have low malignant potential and patients can keep more kidney function.
Radical nephrectomy – Removes the entire kidney, surrounding fat, and sometimes adrenal gland and lymph nodes. This is used for large or more complex tumours, or when partial nephrectomy is not technically safe. It aims for complete tumour clearance at the cost of reduced overall kidney reserve.
Lymph-node dissection – If imaging or surgery suggests involved regional lymph nodes, surgeons may remove them at nephrectomy. This helps with staging and may improve local control in selected patients, although the survival benefit is debated. The main mechanism is removing sites of potential spread and providing accurate pathologic information.
Metastasectomy (removal of isolated metastases) – In some patients with a few metastases, such as a single lung or bone lesion, surgery to remove these spots can be considered. This may be combined with systemic therapy and can sometimes lead to long-term disease control. It works by reducing total tumour burden to a level where the immune system and drugs can manage the rest.
Minimally invasive and robotic techniques – Laparoscopic or robotic partial and radical nephrectomy can reduce blood loss, pain and hospital stay compared to open surgery, while offering similar cancer control in experienced hands. The mechanism is purely technical: smaller incisions and precise instrument control, which leads to faster recovery and earlier return to normal activities.
Prevention and risk-reduction
Even though multilocular cystic tumours often have an excellent prognosis, general kidney-cancer prevention and kidney-health strategies are still important:
Avoid smoking – Stopping smoking lowers kidney-cancer risk and improves outcomes after diagnosis.
Maintain a healthy body weight – Gradual weight loss through diet and activity reduces metabolic and inflammatory stress on kidneys.
Control blood pressure and diabetes – Good control protects kidney function and lowers cardiovascular risk.
Limit long-term heavy NSAID use – Avoid frequent high-dose pain-killer use without medical advice.
Healthy, plant-forward diet – Emphasise fruits, vegetables, whole grains and lean proteins, while limiting processed meats and very salty foods.
Stay physically active – Regular moderate exercise supports immune health, weight, blood pressure and mood.
Protect from occupational toxins – Use proper safety equipment if working with industrial solvents or heavy metals.
Hydrate sensibly – Adequate fluids (unless restricted by your doctor) support kidney function and help prevent stones.
Know your family-history risks – People with hereditary syndromes like VHL need specialised screening and early management.
Attend regular check-ups – Routine blood pressure, kidney-function tests and imaging when indicated can detect problems earlier.
When to see doctors
You should seek medical review promptly if you notice blood in urine, persistent flank or back pain, a new abdominal lump, unexplained weight loss, fevers, night sweats, or extreme tiredness – these can be signs of kidney cancer or recurrence.
During and after treatment, contact your oncology team urgently if you develop sudden shortness of breath, chest pain, severe diarrhoea, bad skin reactions, confusion, very little urine, or strong new pain, especially while on immunotherapy or targeted drugs, because these side effects can sometimes be serious but treatable if caught early.
What to eat and what to avoid
Emphasise colourful vegetables and fruits – Aim for a variety of colours every day, unless your team has given specific potassium or oxalate limits. They supply vitamins, minerals, antioxidants and fibre that support healing and energy.
Choose mostly whole grains – Brown rice, oats, barley and whole-grain breads provide fibre and slow-release energy, helping maintain stable blood sugar and bowel regularity during treatment.
Use kidney-friendly proteins – Include moderate portions of lean poultry, fish, eggs and plant proteins like beans and lentils, adjusted to your kidney function by a dietitian. Too much protein can stress the kidney, while too little harms muscle mass.
Limit processed and red meats – Bacon, sausages, ham and large amounts of red meat are high in salt, saturated fat and preservatives, which may increase cardiovascular and kidney burden. Use small portions occasionally rather than daily staples.
Cut back on very salty foods – Packet snacks, instant soups, fast foods and many frozen meals contain lots of sodium, which raises blood pressure and harms kidney function. Cooking fresh meals and tasting before adding salt is kinder to the remaining kidney.
Avoid sugary drinks and excess soda – Sugary and diet soft drinks are linked with metabolic problems and can increase kidney-stone and kidney-disease risk. Water, infused water, and unsweetened herbal teas are usually better choices.
Use healthy fats instead of butter and heavy mayonnaise – Swap to small amounts of olive or canola oil, nuts and seeds for healthier fats that support heart and vessel health without overloading kidneys.
Be cautious with high-oxalate foods if prone to stones – Foods like large amounts of raw beetroot, spinach and some nuts can raise oxalate levels; boiling beetroot markedly lowers oxalate content, so cooked forms in moderation may be safer.
Limit alcohol and completely avoid smoking – Alcohol should be kept within or below national guidelines, and many patients are advised to avoid it entirely during treatment. Smoking cessation is one of the strongest positive steps you can take.
Follow personalised advice from a renal or oncology dietitian – Because every patient’s kidney function, treatment plan and body size are different, an individual diet plan is more accurate than any generic list. Always share any supplements or special diets you are considering.
Frequently asked questions (FAQs)
1. Is a cystic-multilocular Grawitz tumour always cancer?
Many multilocular cystic kidney lesions are now classified as “multilocular cystic renal neoplasms of low malignant potential,” meaning they do contain tumour cells but behave very gently, with an extremely low risk of spread when fully removed. Pathology review after surgery is essential to classify the exact subtype.
2. What is the usual treatment for localised multilocular cystic tumours?
For most localised lesions, partial or radical nephrectomy is the main treatment, and many patients do not need systemic drugs afterwards because prognosis is excellent. Decisions depend on tumour size, location, patient age, kidney function and other health conditions.
3. If it spreads, is treatment the same as for other clear-cell RCC?
Yes. Once the disease behaves like advanced clear-cell RCC, doctors usually follow the same guidelines, using combinations of immunotherapy and targeted drugs such as pembrolizumab, nivolumab, IPIs and TKIs, selected according to risk category and prior treatment.
4. How successful are modern treatments for advanced RCC?
Modern combinations have improved survival and response rates compared with older therapies, and some patients experience long-lasting remissions. However, responses vary widely, and no current systemic treatment guarantees cure in widely metastatic disease.
5. Do all patients need drug treatment after surgery?
No. Many people with completely removed, low-risk cystic tumours are managed with observation and follow-up imaging only. Adjuvant immunotherapy is generally reserved for patients with higher-risk features after nephrectomy.
6. Can diet alone cure a Grawitz tumour?
No diet or supplement has been proven to cure kidney cancer. A healthy, kidney-friendly eating pattern can support strength, immune function and tolerance of surgery and drugs, but it must be seen as supportive, not as a replacement for evidence-based medical treatment.
7. Are “stem-cell clinics” offering cures for kidney cancer safe?
Unregulated stem-cell clinics often make promises not supported by clinical trials and can expose patients to infections, unexpected immune reactions and financial exploitation. Evidence-based regenerative approaches for RCC are still mainly in controlled clinical-trial settings.
8. Will losing one kidney shorten my life?
Many people live long, healthy lives with one kidney, especially when blood pressure, weight and diabetes are well controlled. Regular follow-up and kidney-protective lifestyle changes are important to reduce long-term risk of chronic kidney disease.
9. Can I become pregnant or father children after treatment?
Some treatments can affect fertility or harm a developing baby, and drugs like belzutifan have specific embryo-foetal toxicity warnings. People of reproductive age should discuss fertility preservation and contraception with their oncology team before starting treatment.
10. How often will I need scans after surgery?
Follow-up schedules vary with stage and risk, but typically involve periodic CT or MRI scans and labs over several years, then less often if everything stays stable. Your team will follow guideline-based intervals adapted to your personal situation.
11. Are targeted drugs and immunotherapy taken for life?
Most systemic therapies are continued until the cancer clearly progresses or side effects become unacceptable. Some immunotherapy combinations are given for a fixed number of cycles or up to a maximum duration; others are stopped earlier if a deep, durable response occurs.
12. What side effects should I report right away?
You should urgently report chest pain, shortness of breath, severe diarrhoea, confusion, high fever, yellow eyes, very reduced urine, or sudden strong weakness, as these can signal serious but treatable adverse events from immunotherapy or TKIs.
13. Is there any benefit in joining a support group?
Many patients find kidney-cancer support groups helpful for sharing practical tips, emotional support, and up-to-date information. Peer support can reduce isolation and improve coping during long-term follow-up.
14. How important is blood-pressure control after nephrectomy?
Blood-pressure control is crucial, because high pressure damages the delicate filters in the remaining kidney and can speed progression to chronic kidney disease. Lifestyle measures and medications may be needed to keep readings in the target range.
15. What is the overall outlook for multilocular cystic renal tumours?
For truly multilocular cystic renal neoplasms of low malignant potential that are completely removed, long-term prognosis is usually excellent, with very rare metastases. When tumours are more aggressive or already advanced, outlook depends on stage, response to therapy, and overall health, but modern treatments are steadily improving outcomes.
Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.
The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members
Last Updated: January 28, 2025.
