Hornstein–Knickenberg Syndrome

Other names
Types
Causes
Symptoms and signs
Diagnostic tests
Non-pharmacological treatments (therapies & other measures)
Drug treatments
Dietary molecular supplements
Immunity-booster / regenerative / stem-cell drugs
Surgeries
Preventions
When to see doctors
What to eat and what to avoid
Frequently asked questions (FAQ)

Hornstein–Knickenberg syndrome is a rare, inherited condition. It runs in families in an autosomal-dominant way, so a parent can pass it to a child. It is caused by a harmful change (mutation) in a gene called FLCN (folliculin). People with this condition often develop three main features over their lifetime: small skin bumps from hair-follicle growths (fibrofolliculomas), lung cysts that can lead to a collapsed lung (spontaneous pneumothorax), and a higher-than-usual risk of kidney tumors (often chromophobe renal cell carcinoma, oncocytoma, or hybrid types). Doctors now consider “Hornstein–Knickenberg syndrome” and “Birt–Hogg–Dubé syndrome” to be the same disease. NCBI+1

Hornstein–Knickenberg syndrome is now considered the same condition as Birt–Hogg–Dubé syndrome (BHD). It is a rare, inherited disorder caused by harmful changes (variants) in the FLCN gene (folliculin). People with BHD typically develop small, benign skin bumps called fibrofolliculomas, air-filled lung cysts that raise the risk of spontaneous pneumothorax (collapsed lung), and a higher lifetime risk of kidney (renal) tumors that are often slow-growing but can be multiple and bilateral. NCBI+2Orpha+2

BHD is passed in an autosomal dominant way, which means a child has a 50% chance of inheriting the condition if one parent carries the FLCN variant. Disease severity varies even within the same family: some people mainly have skin bumps, others have lung problems or kidney tumors. Genetic testing confirms the diagnosis and helps identify at-risk relatives who need screening. NCBI+1

Historically, the name “Hornstein–Knickenberg syndrome” was used for families with fibrofolliculomas and colon polyps; modern genetics clarified that this eponym describes the same entity as BHD caused by FLCN variants. Today’s medical genetics resources list Hornstein–Knickenberg syndrome as an alias of BHD. NCBI+1

Other names

Hornstein–Knickenberg syndrome; Birt–Hogg–Dubé syndrome (BHD); Hornstein–Birt–Hogg–Dubé syndrome; familial multiple perifollicular fibromas; fibrofolliculomas with trichodiscomas and acrochordons. These names reflect how different teams first described the same condition in the 1970s. NCBI+1

Types

There is no official set of “types,” but doctors often talk about clinical patterns because families can show different mixes of features. Think of these as useful groupings, not separate diseases:

Skin-predominant pattern. People mainly have many small, skin-colored bumps (fibrofolliculomas) on the face, neck, and upper trunk, sometimes with trichodiscomas or skin tags. Kidneys and lungs may be less affected. Dove Medical Press
Lung-predominant pattern. Lung cysts and repeated spontaneous pneumothorax are the leading problems, often starting in early to mid-adulthood. Skin signs may be mild or late. Dove Medical Press
Kidney-predominant pattern. The main risk is kidney tumors (often multiple or on both sides). Early and regular imaging is important here. NCBI
Mixed pattern. Many people have a mix of skin bumps, lung cysts, and kidney tumors at different ages. Penetrance is high across a lifetime. NCBI

Causes

Remember: the root cause is an FLCN gene mutation. The items below describe genetic and biologic mechanisms, plus triggers that shape how the condition shows up.

Germline FLCN loss-of-function mutation. The core cause in almost all families. NCBI
Haploinsufficiency of folliculin. One good copy is not enough; folliculin levels fall and tissue control is altered. NCBI
Second-hit (somatic) mutation in tissues. A second change in the same gene inside a skin, lung, or kidney cell can tip that cell toward a tumor or cyst. NCBI
mTOR/AMPK pathway dysregulation. Folliculin normally helps cells sense nutrients and energy; signaling drift promotes hamartomas and tumors. Dove Medical Press
Abnormal hair-follicle growth control. This favors benign skin tumors like fibrofolliculomas. NCBI
Cyst formation in lung tissue. Weak points develop in alveolar walls, making air-filled cysts. Dove Medical Press
Predisposition to pneumothorax. Lung cysts can rupture and cause a collapsed lung. Dove Medical Press
Kidney-tumor predisposition. Loss of folliculin control can lead to oncocytic and chromophobe kidney tumors. NCBI
Specific FLCN hotspots (e.g., c.1285dupC). Some variants are common in certain populations but do not show stable genotype-phenotype prediction. Dove Medical Press+1
Age-related penetrance. Features often appear with age; most carriers develop something during life. NCBI
Family history (autosomal dominant). Each child has a 50% chance to inherit the variant. NCBI
De novo mutation. Sometimes a person is the first in the family to carry the variant. NCBI
Genetic mosaicism. A post-zygotic change can produce patchy involvement; rarely, mosaic parents transmit the variant. (Mosaicism is reported across related adnexal tumor syndromes.) ResearchGate
Modifier genes (probable). Other genes likely shape how severe the skin, lung, or kidney features are. Dove Medical Press
Smoking. Not causal, but may worsen lung injury and increase pneumothorax risk. Dove Medical Press
Pressure changes (flying, diving). Pressure swings may trigger cyst rupture in predisposed lungs. Dove Medical Press
Hormonal/physiologic stress. Illness or surgery may unmask lung or skin issues in some people. (General clinical inference consistent with BHDS care.) NCBI
Somatic FLCN changes in sporadic tumors. FLCN can be altered in non-inherited tumors, showing its tumor-suppressor role. NCBI
Possible colon-polyp pathway. Early reports described colonic polyps; whether colon cancer risk is truly increased remains debated. NCBI
Thyroid nodules (association). Thyroid nodules and goiter are reported; a firm causal link to thyroid cancer is uncertain. NCBI

Symptoms and signs

Not everyone has every symptom. Many are mild for years.

Small, smooth, skin-colored bumps on face/neck (fibrofolliculomas). Often appear after age 20–30; may slowly increase in number. NCBI
Trichodiscomas and skin tags. Other benign skin growths that look similar and can coexist. Dove Medical Press
Lung cysts. Usually found on CT scans; most people do not feel them until a problem occurs. Dove Medical Press
Spontaneous pneumothorax (collapsed lung). Sudden chest pain and shortness of breath; often recurs without preventive treatment. Dove Medical Press
Shortness of breath with exertion. Can follow lung cyst growth or small pneumothoraxes. Dove Medical Press
Kidney tumors. Many are slow-growing; some cause flank pain or blood in urine, but many are silent. NCBI
Blood in urine (hematuria). May signal a kidney tumor or other kidney issue. NCBI
Flank or back discomfort. Can occur with kidney mass or cyst. NCBI
Cosmetic concerns from facial bumps. Common reason people seek care. Dove Medical Press
Anxiety around flying or diving. Due to fear of lung collapse; personalized counseling helps. Dove Medical Press
Thyroid nodules or goiter. Often asymptomatic; found on ultrasound. NCBI
Skin cancer (occasionally). Basal cell carcinoma and other rare tumors have been reported. NCBI
Kidney cysts (non-cancer). Harmless fluid sacs sometimes occur with or without tumors. NCBI
Family clustering. Multiple relatives with pneumothorax, kidney tumors, or facial bumps suggest the diagnosis. Dove Medical Press
Often otherwise healthy. Many people feel well and learn of the condition only after a lung event or during imaging. Dove Medical Press

Diagnostic tests

A) Physical exam

Full skin inspection. A dermatologist looks for many tiny, smooth, dome-shaped papules on the face, ears, neck, and chest—classic fibrofolliculomas/trichodiscomas. NCBI
Family history mapping. Clinician documents relatives with collapsed lungs, kidney tumors, or similar skin bumps across generations. Dove Medical Press
General exam for syndromic clues. Looks for acrochordons, thyroid enlargement, or other unusual lumps. NCBI
Blood pressure and abdominal palpation. Screens for kidney mass effects and overall health before imaging. (General clinical practice.)
Post-pneumothorax chest assessment. Re-exam after recovery to decide on prevention and imaging. Dove Medical Press

B) “Manual”/bedside tests

Dermatoscopy of skin papules. Noninvasive magnified look that supports a follicular origin before biopsy. (Dermatology standard adjunct.)
Pulse oximetry. A finger sensor checks oxygen levels if breathing symptoms occur. (Pulmonary care standard.)
Simple breath assessment (peak flow/spirometry screening). Bedside or clinic spirometry can note airflow change after a pneumothorax. (Pulmonary practice.)
Urine dipstick. Quick screen for blood in the urine that may prompt imaging for tumors. (Urology practice.)
Thyroid palpation. Hands-on check for nodules that later get ultrasound confirmation. NCBI

C) Laboratory & pathology tests

Skin biopsy with histology. Confirms fibrofolliculoma (or perifollicular fibroma) under the microscope—this clinches the skin diagnosis. PubMed
Germline FLCN gene testing. Sequencing plus deletion/duplication analysis to detect the familial variant. This is the gold standard confirmation. NCBI
Targeted family testing. Once the variant is known, relatives can be tested for that specific change. NCBI
Kidney tumor pathology (if removed). Helps classify chromophobe, oncocytoma, or hybrid tumors—common in this syndrome. NCBI
Basic blood tests (renal function). Creatinine and eGFR guide safe use of contrast and overall kidney health. (General oncology/urology practice.)

D) Electrodiagnostic/physiology tests

Formal spirometry. Measures lung volumes and flows; often normal between events but helpful after pneumothorax. Dove Medical Press
Arterial blood gas during acute pneumothorax. Assesses oxygen and carbon dioxide when someone is very short of breath. (Emergency standard.)
ECG (if chest pain). Rules out cardiac causes of chest pain in emergency settings. (Emergency standard.)

E) Imaging tests

High-resolution chest CT (HRCT). Best test to show multiple lung cysts with typical lower-lobe and basilar distribution; supports diagnosis. Dove Medical Press
Chest X-ray. Quick way to confirm a collapsed lung during symptoms; less sensitive for cysts. Dove Medical Press
Renal MRI (preferred for surveillance). Sensitive for small kidney tumors and avoids radiation from repeated CT scans. (Management recommendations in major reviews.) NCBI
Renal ultrasound. Good first look; if anything is suspicious or small, MRI adds detail. (Urology practice.)
Abdominal CT (when needed). Used selectively when MRI is not available or for surgical planning. (Oncology imaging practice.)
Thyroid ultrasound. Checks nodules/goiter when present; cancer risk linkage is uncertain, but nodules are common in series. NCBI
Colonoscopy (case-by-case). Early reports described colonic polyps, but colon-cancer risk is uncertain; many experts follow general-population screening unless there is a family history. NCBI

Non-pharmacological treatments (therapies & other measures)

1) Lifelong kidney (renal) surveillance
Purpose: Find kidney tumors early and preserve kidney function.
Mechanism: Regular MRI (often yearly or every 1–2 years in adults) detects small tumors so surgeons can plan nephron-sparing procedures when needed (often using a 3-cm intervention threshold individualized by experts). PMC+1

2) Kidney-sparing surgery planning
Purpose: Remove tumors while protecting as much kidney tissue as possible.
Mechanism: Partial nephrectomy or ablative options for localized tumors minimize loss of kidney function, guided by urologic oncology teams. CloudFront

3) Early treatment of pneumothorax (collapsed lung)
Purpose: Re-expand the lung, relieve breathlessness, and prevent complications.
Mechanism: Oxygen, observation, or chest tube drainage depending on size and symptoms; recurrence risk is high in BHD, so definitive measures are planned early. NCBI

4) Preventive pleurodesis after first pneumothorax
Purpose: Reduce the high chance of another collapse.
Mechanism: Surgical or chemical pleurodesis adheres lung to chest wall; often advised after the first event in BHD due to recurrent risk. PMC

5) VATS bullectomy with pleurodesis (selected cases)
Purpose: Remove culprit blebs/cysts and prevent recurrence.
Mechanism: Video-assisted thoracoscopic surgery (VATS) removes fragile blebs and seals the pleural space; used per contemporary pneumothorax guidance. Medscape

6) Air travel and pressure-change counseling
Purpose: Lower risk of in-flight or diving-related pneumothorax.
Mechanism: Individualized advice after lung cyst assessment; avoid unpressurized flights or diving unless cleared by respiratory experts. PMC

7) Smoking cessation
Purpose: Protect lungs and overall health.
Mechanism: Stopping smoking reduces general pneumothorax risk and improves surgical outcomes for chest and kidney procedures. PMC

8) Dermatologic procedures for fibrofolliculomas
Purpose: Improve appearance and comfort.
Mechanism: Specialist treatments (e.g., laser ablation, electrosurgery) remove or reduce bumps; lesions often recur, so treatments are repeated as needed. NCBI

9) Sun protection
Purpose: Protect skin with numerous lesions and reduce photo-related irritation.
Mechanism: Sunscreens, shade, and clothing reduce UV stress on skin with fibrofolliculomas. NCBI

10) Genetic counseling & family testing
Purpose: Identify relatives who need surveillance and avoid unnecessary testing in those without the variant.
Mechanism: Confirmed FLCN variant enables cascade testing; only carriers need renal and lung surveillance. NCBI

11) Multidisciplinary clinic follow-up
Purpose: Coordinate care across dermatology, pulmonology, urology, radiology, and genetics.
Mechanism: Team-based plans align surveillance intervals and surgical timing for best long-term kidney and lung outcomes. PMC

12) Individualized renal imaging choice
Purpose: Balance sensitivity and radiation exposure.
Mechanism: MRI is often preferred for repeated lifetime surveillance; CT is used when clinically necessary. National Cancer Institute

13) Structured symptom education
Purpose: Speed recognition of pneumothorax or kidney issues.
Mechanism: Teach warning signs (sudden chest pain/shortness of breath; new flank pain, blood in urine) and emergency steps. PMC

14) Post-op pulmonary rehab (selected patients)
Purpose: Improve recovery after chest surgery.
Mechanism: Breathing exercises and graded activity rebuild lung function and endurance. Medscape

15) Occupational counseling (high-risk jobs)
Purpose: Reduce risk where recurrence would endanger self/others (e.g., pilots).
Mechanism: Consider definitive pleurodesis before returning to high-risk pressure environments. Nature

16) Psychological support
Purpose: Manage anxiety around lifelong surveillance and surgeries.
Mechanism: Access to counseling and patient groups improves coping and adherence. Genturis

17) Vaccination per national schedules
Purpose: Reduce respiratory infections that complicate cystic lungs.
Mechanism: Routine influenza and pneumococcal vaccination reduce infection-related exacerbations (general respiratory care principle). PMC

18) Healthy activity with safety planning
Purpose: Maintain fitness while limiting barotrauma risk.
Mechanism: Low-impact exercise is encouraged; avoid extreme pressure swings without specialist clearance. PMC

19) Nutrition & kidney health counseling
Purpose: Support overall health during surveillance and after nephron-sparing surgery.
Mechanism: Adequate hydration and balanced diet support renal function alongside medical care. CloudFront

20) Patient-held records
Purpose: Keep imaging dates, results, and surgical history handy.
Mechanism: A shared record helps teams time scans and plan interventions. PMC

Drug treatments

Plain English note: No medicine reverses the genetic cause of BHD. When kidney cancer occurs, doctors use standard, FDA-approved RCC medicines. The choice depends on tumor stage, prior therapy, and the care team’s judgment. Doses below are from FDA labels (not personal medical advice).

Sunitinib (SUTENT) — oral TKI for advanced RCC. Typical dosing: 50 mg once daily, 4 weeks on/2 weeks off (other schedules exist). Blocks VEGF and PDGF signaling to slow tumor blood vessel growth; common side effects: fatigue, diarrhea, hand-foot reaction, hypertension. FDA Access Data
Pazopanib (VOTRIENT) — oral TKI for advanced RCC. Typical dosing: 800 mg once daily on empty stomach. Inhibits VEGFR, PDGFR, KIT; monitor liver tests due to hepatotoxicity warning. FDA Access Data
Cabozantinib (CABOMETYX) — oral TKI for RCC across several settings (including after prior therapy; combinations also used). Label includes detailed dosing and surgery timing precautions; adverse effects include diarrhea, hand-foot syndrome, hypertension. FDA Access Data
Pembrolizumab (KEYTRUDA) — IV anti-PD-1 immunotherapy used in RCC (adjuvant and metastatic combinations). Immune-related side effects include thyroiditis, colitis, hepatitis; dosing is weight- or flat-dose per label. FDA Access Data
Nivolumab (OPDIVO) — IV anti-PD-1 for RCC (alone or with ipilimumab). Immune toxicities (e.g., pneumonitis, colitis) require protocol-based management. FDA Access Data
Axitinib (INLYTA) — oral TKI used after prior therapy and in first-line when combined with pembrolizumab or avelumab. Typical monotherapy dose: 5 mg twice daily, adjusted for tolerance. FDA Access Data
Lenvatinib (LENVIMA) — oral TKI used with pembrolizumab (first-line) or with everolimus (after prior anti-angiogenic therapy) in RCC. Labels specify which agent to dose-reduce first in combinations. FDA Access Data+1
Everolimus (AFINITOR) — oral mTOR inhibitor for advanced RCC after sunitinib or sorafenib. Typical dose: 10 mg once daily; watch for mouth ulcers, infections, and metabolic effects. FDA Access Data
Temsirolimus (TORISEL) — IV mTOR inhibitor for advanced RCC (noted activity in poor-risk disease). Mechanism targets mTOR pathway, affecting tumor growth and angiogenesis. FDA Access Data
Sorafenib (NEXAVAR) — oral multikinase inhibitor for advanced RCC. Typical dose: 400 mg twice daily; acts on RAF and VEGF pathways; hand-foot reaction and hypertension are common. FDA Access Data
Ipilimumab (YERVOY) — IV anti-CTLA-4; used with nivolumab for previously untreated intermediate/poor-risk RCC. Requires careful immune-toxicity monitoring per label. FDA Access Data
Avelumab (BAVENCIO) — IV anti-PD-L1; with axitinib for first-line advanced RCC; label details dose (800 mg q2 weeks) and premedication guidance. FDA Access Data
Cabozantinib + Nivolumab — commonly used combination (components above); label documents RCC indications and dosing details for each drug. FDA Access Data+1
Pembrolizumab + Lenvatinib — first-line RCC combination; labels specify indications and dose-modification strategy. FDA Access Data
Axitinib + Pembrolizumab — first-line combination; label covers dosing and adverse-event management. FDA Access Data
Axitinib + Avelumab — first-line combination option; label provides dose and safety requirements (including infusion reactions). FDA Access Data
Cabozantinib (monotherapy) after prior therapy — FDA-approved in RCC with multiple label updates; see current label for dosing and perioperative guidance. FDA Access Data
Pembrolizumab (adjuvant RCC) — given after nephrectomy in patients at higher risk of recurrence; dosing and KEYNOTE-564 details appear in the label. FDA Access Data
Sunitinib (alternative dosing schedules) — labels describe standard and alternative schedules; clinicians tailor based on tolerance. FDA Access Data
Pazopanib (updated labeling) — current label reiterates RCC indication and hepatic monitoring requirements. FDA Access Data

Important safety note: These drugs are prescribed by oncology specialists for kidney cancer associated with BHD when it occurs. They are not used to treat benign skin lesions or lung cysts in BHD. Treatment plans are individualized and follow evolving oncology guidelines. Annals of Oncology

Dietary molecular supplements

Plain English caution: Evidence for supplements in BHD is limited. Use them only if your clinician agrees, especially when taking TKIs or immunotherapy.

Vitamin D — supports bone/immune health; deficiency is common; dosing individualized to achieve normal serum 25-OH D under clinician guidance. (General supportive evidence; not BHD-specific.) PMC
Omega-3 fatty acids (fish oil) — may help general cardiovascular health and inflammation balance; check bleeding risk if on targeted therapies. (General supportive evidence.) Annals of Oncology
Green tea extract (EGCG) — antioxidant/AMPK effects; avoid high-dose concentrates with TKIs without medical approval. (General oncology nutrition caution.) Annals of Oncology
Curcumin — anti-inflammatory pathways (NF-κB); potential drug–supplement interactions require oncology approval. (General evidence.) Annals of Oncology
Selenium — antioxidant cofactor; deficiency replacement only; excess is harmful. (General nutrition guidance.) Annals of Oncology
Lycopene (tomato extract) — antioxidant; sometimes studied in prostate/kidney health; food-first approach preferred. (General evidence.) Annals of Oncology
Resveratrol — polyphenol with antioxidant signaling; data are mixed; discuss with your doctor. (General evidence.) Annals of Oncology
Coenzyme Q10 — mitochondrial cofactor; may support energy in some patients; interactions possible. (General evidence.) Annals of Oncology
Probiotics — gut microbiome support during systemic therapy; pick clinically studied strains; stop if immunocompromised unless advised. (General supportive care.) Annals of Oncology
Protein-rich nutrition (food first; whey if needed) — supports recovery after surgery; dietitian can tailor to renal function. (General peri-operative nutrition guidance.) CloudFront

Immunity-booster / regenerative / stem-cell drugs

There are no FDA-approved “immunity booster,” regenerative, or stem-cell drugs for BHD. Stem-cell or “regen” clinics marketing cures for genetic syndromes like BHD are not evidence-based. Immune function is best supported by vaccination, sleep, nutrition, and infection prevention. If kidney cancer occurs, evidence-based RCC immunotherapies (e.g., pembrolizumab, nivolumab) are used to treat cancer, not to “boost” general immunity. Participation in regulated clinical trials is the appropriate route for experimental therapies. PMC+2FDA Access Data+2

Surgeries

1) Partial nephrectomy (kidney-sparing surgery)
Procedure: Remove the tumor while leaving the rest of the kidney.
Why: Preserves kidney function because BHD tumors can be multiple/bilateral over a lifetime; often favored when feasible. CloudFront

2) Radical nephrectomy
Procedure: Remove the entire kidney when tumors are large, numerous, or poorly placed for partial surgery.
Why: Sometimes necessary for oncologic safety; decided by urology and oncology teams. National Cancer Institute

3) Ablation (cryoablation or radiofrequency)
Procedure: Needle-based freezing/heating destroys small tumors.
Why: An option for selected localized tumors in patients who are surgical candidates or to preserve kidney tissue. Genturis

4) VATS bullectomy and pleurodesis
Procedure: Thoracoscopic removal of fragile blebs/cysts with pleural adhesion.
Why: Reduces recurrence of pneumothorax in BHD, where repeats are common. PMC

5) Dermatologic lesion removal (laser/electrosurgery)
Procedure: Office-based destruction or excision of fibrofolliculomas.
Why: Cosmetic improvement and relief of irritation; recurrence is possible and retreatment is common. NCBI

Preventions

Do not smoke (protects lungs and surgery outcomes). PMC
Follow lifelong renal imaging schedules exactly. PMC
Learn pneumothorax signs and seek urgent care for sudden chest pain or breathlessness. PMC
Consider pleurodesis early after the first collapse to prevent recurrence. PMC
Get genetic counseling so relatives know if they need screening. NCBI
Practice sun protection for lesion-prone skin. NCBI
Keep an updated care plan and carry emergency info when flying/traveling. PMC
Maintain healthy weight, activity, and hydration to support kidneys. CloudFront
Stay up-to-date on vaccines (e.g., influenza, pneumococcal) per general guidance. PMC
Use a multidisciplinary clinic and attend all follow-ups. PMC

When to see doctors

Seek urgent care now for sudden, sharp chest pain and shortness of breath (possible pneumothorax). Arrange prompt review for new flank pain, blood in urine, or a palpable abdominal mass (possible kidney issue). Schedule dermatology if skin bumps rapidly change, bleed, or become bothersome. Genetic counseling is advised if you or a first-degree relative has features of BHD or a confirmed FLCN variant. NCBI+1

What to eat and what to avoid

Eat: (1) plenty of vegetables and fruits; (2) whole grains; (3) lean proteins and plant proteins; (4) healthy fats (e.g., olive oil, nuts); (5) adequate fluids (unless restricted); (6) calcium- and vitamin-D-containing foods; (7) fiber-rich foods for metabolic health; (8) modest sodium to protect kidneys; (9) iron-rich foods if needed post-op; (10) small, frequent meals during systemic therapy if used.

Avoid/limit: excessive salt, heavy alcohol, sugary drinks, and unregulated supplements that can interact with RCC drugs; always clear supplements with your oncology team. CloudFront

Frequently asked questions (FAQ)

1) Is Hornstein–Knickenberg syndrome the same as BHD?
Yes. Modern genetics shows Hornstein–Knickenberg syndrome is identical to BHD, caused by FLCN variants. NCBI

2) What are the main signs?
Face/neck fibrofolliculomas, lung cysts with risk of collapsed lung, and kidney tumors that can be multiple and bilateral. NCBI

3) How is it inherited?
Autosomal dominant; each child of an affected parent has a 50% chance of inheriting the variant. NCBI

4) How do you confirm the diagnosis?
Clinical features plus FLCN genetic testing; testing helps direct surveillance to the right family members. NCBI

5) How often should kidneys be imaged?
Guidelines recommend lifelong surveillance in adults (often MRI at regular intervals, individualized by experts). PMC

6) When is kidney surgery needed?
When tumors reach an agreed size threshold or grow/change; partial nephrectomy is preferred when possible to save kidney tissue. CloudFront

7) Can the lung collapse happen more than once?
Yes; recurrence is common in BHD, which is why pleurodesis is often advised after the first event. PMC

8) Can I fly or dive?
Discuss with your lung specialist; pressure changes can trigger pneumothorax in people with lung cysts. PMC

9) Do medicines fix BHD?
No medicine fixes the genetic cause. Medicines treat kidney cancer, if it occurs, using standard RCC drugs. Annals of Oncology

10) Which cancer drugs are used if I get RCC?
Options include TKIs (e.g., sunitinib, pazopanib, axitinib, cabozantinib, lenvatinib), mTOR inhibitors (everolimus, temsirolimus), and immunotherapies (pembrolizumab, nivolumab, ipilimumab)—alone or in combinations per labels and guidelines. FDA Access Data+7FDA Access Data+7FDA Access Data+7

11) Are there “immune boosters” or stem-cell cures?
No approved regenerative or stem-cell drugs exist for BHD; avoid unproven treatments outside regulated trials. PMC

12) What about the skin bumps—do they turn cancerous?
Fibrofolliculomas are benign; treatment is usually for appearance or irritation (e.g., laser/electrosurgery). NCBI

13) Is colon cancer part of BHD?
Earlier reports suggested an association, but evidence is mixed; current guidelines focus on kidney, lung, and skin. Follow standard population colon screening unless your clinician advises otherwise. NCBI

14) Should my family be tested?
Yes, if a pathogenic FLCN variant is found in you; relatives can have targeted testing to guide surveillance. NCBI

15) Where can I find clinician-level guidance?
See the ERN GENTURIS 2024 clinical practice guidelines and GeneReviews for detailed surveillance and management recommendations. PMC+1

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.