Malignant pilomatricoma, also known as malignant pilomatrixoma, is a rare form of skin cancer that arises from cells called pilomatricomas. Pilomatricomas are benign tumors that develop from hair follicle cells, which are responsible for producing hair. They usually present as solitary, slow-growing, firm, mobile, painless nodules that are located most commonly on the face, neck, and upper extremities. Malignant pilomatrixoma, on the other hand, is a malignant transformation of these benign tumors, which accounts for less than 1% of all cases of pilomatrixoma.
Malignant pilomatricoma, also known as pilomatrical carcinoma, is a rare skin tumor that arises from hair follicle cells. It is an aggressive form of pilomatricoma, a benign tumor, that can potentially metastasize to other parts of the body.
Types
Malignant pilomatrixoma is classified as a type of skin adnexal tumor, which is a group of tumors that arise from the various structures associated with the skin, such as hair follicles, sweat glands, and sebaceous glands. These tumors are further divided into benign and malignant types based on their behavior and ability to spread to other parts of the body.
There are several different types of malignant pilomatrixoma, which are classified based on their histological features and clinical behavior. The most common type is the infiltrative or invasive type, which is characterized by the infiltration of tumor cells into the surrounding tissues, such as subcutaneous fat, muscle, and bone. This type of tumor has a higher potential for recurrence and metastasis to other organs, such as the lungs and bones.
Another type of malignant pilomatrixoma is the metastatic type, which is characterized by the spread of tumor cells to distant sites, such as the lymph nodes, lungs, and liver. This type of tumor is associated with a poor prognosis and a high risk of mortality.
Other less common types of malignant pilomatrixoma include the atypical type, which is characterized by abnormal cellular and nuclear features, and the spindle cell type, which is characterized by elongated spindle-shaped tumor cells.
Causes
There are several causes of malignant pilomatricoma, including genetic mutations, environmental factors, and other underlying medical conditions. Below are possible causes of malignant pilomatricoma, along with an explanation of each:
- Genetic mutations: Mutations in certain genes can increase the risk of developing malignant pilomatricoma. These mutations can be inherited or acquired over time. Inherited mutations are passed down from parents to their children, while acquired mutations occur as a result of exposure to environmental factors or other causes.
- Radiation exposure: Exposure to ionizing radiation, such as X-rays or gamma rays, can damage cells and increase the risk of developing cancer, including malignant pilomatricoma.
- Chemical exposure: Exposure to certain chemicals, such as arsenic or vinyl chloride, can also increase the risk of developing malignant pilomatricoma.
- Sun exposure: Prolonged exposure to the sun’s ultraviolet (UV) rays can damage skin cells and increase the risk of developing skin cancer, including malignant pilomatricoma.
- Age: Malignant pilomatricoma is more common in older individuals, particularly those over the age of 50.
- Gender: Malignant pilomatricoma is more common in women than in men.
- Family history: Individuals with a family history of skin cancer or other types of cancer may be at an increased risk of developing malignant pilomatricoma.
- Immune system disorders: Individuals with weakened immune systems, such as those with HIV/AIDS or those who have undergone an organ transplant, may be at an increased risk of developing malignant pilomatricoma.
- Previous cancer treatment: Individuals who have undergone radiation therapy or chemotherapy for other types of cancer may be at an increased risk of developing malignant pilomatricoma.
- Smoking: Smoking is a risk factor for many types of cancer, including malignant pilomatricoma.
- Alcohol consumption: Heavy alcohol consumption can increase the risk of developing many types of cancer, including malignant pilomatricoma.
- Obesity: Obesity has been linked to an increased risk of developing many types of cancer, including malignant pilomatricoma.
- Diabetes: Individuals with diabetes may be at an increased risk of developing malignant pilomatricoma.
- Hormone imbalances: Imbalances in certain hormones, such as estrogen or testosterone, may increase the risk of developing malignant pilomatricoma.
- Viral infections: Certain viral infections, such as human papillomavirus (HPV), have been linked to an increased risk of developing skin cancer.
- Chronic inflammation: Chronic inflammation can damage cells and increase the risk of developing many types of cancer, including malignant pilomatricoma.
- Diet: A diet that is high in fat, processed foods, and red meat has been linked to an increased risk of developing many types of cancer, including malignant pilomatricoma.
- Lack of exercise: A sedentary lifestyle has been linked to an increased risk of developing many types of cancer, including malignant pilomatricoma.
- Stress: Chronic stress can weaken the immune system and increase the risk of developing many types of cancer, including malignant pilomatricoma.
- Environmental factors: Exposure to certain environmental factors, such as pollution or pesticides, can increase the risk of developing many types of cancer, including malignant pilomatricoma.
Symptoms
Here are common symptoms of malignant pilomatricoma, along with details about each symptom:
- Rapid growth: Malignant pilomatricomas tend to grow much more quickly than benign pilomatricomas. This rapid growth is often the first sign of malignancy.
- Large size: Malignant pilomatricomas can grow to be quite large, sometimes measuring several centimeters in diameter.
- Ulceration: As the tumor grows, it can sometimes break through the skin, leading to ulceration.
- Bleeding: Ulceration can cause bleeding, which may be intermittent or continuous.
- Pain: Malignant pilomatricomas can be painful, especially if they are pressing on nerves or other sensitive tissues.
- Redness: The skin around the tumor may become red and inflamed.
- Swelling: As the tumor grows, it can cause swelling in the surrounding tissues.
- Discoloration: The skin around the tumor may become discolored, taking on a purple or reddish hue.
- Nodularity: Malignant pilomatricomas often have a nodular appearance, with a lumpy or bumpy texture.
- Firmness: The tumor may feel firm or hard to the touch, indicating the presence of solid mass.
- Fixation: Malignant pilomatricomas can sometimes become attached to underlying tissues, making them difficult to move or manipulate.
- Enlarged lymph nodes: If the tumor has spread to nearby lymph nodes, these nodes may become enlarged.
- Weight loss: If the tumor has metastasized (spread) to other parts of the body, the patient may experience unexplained weight loss.
- Fatigue: Similarly, metastasis can cause fatigue and a general feeling of malaise.
- Fever: In rare cases, a patient with malignant pilomatricoma may develop a fever.
- Night sweats: Like fever, night sweats can be a sign of advanced malignancy.
- Anemia: Malignant pilomatricoma can cause anemia, which may lead to fatigue, shortness of breath, and other symptoms.
- Jaundice: If the tumor has spread to the liver, the patient may develop jaundice, a yellowing of the skin and eyes.
- Ascites: In advanced cases, malignant pilomatricoma can cause ascites, a buildup of fluid in the abdomen that can cause discomfort and swelling.
- Neurological symptoms: If the tumor has spread to the brain or spinal cord, the patient may experience neurological symptoms such as headaches, seizures, and difficulty with movement or coordination.
Diagnosis
Malignant pilomatricoma can be challenging to diagnose clinically and histologically, and there is no consensus on the optimal management of this disease. In this article, we will discuss different diagnosis and tests for malignant pilomatricoma in detail.
- Clinical examination: The diagnosis of malignant pilomatricoma is primarily based on clinical examination, which involves a thorough examination of the skin lesion. Malignant pilomatricoma typically presents as a firm, painless, slow-growing mass on the head and neck region. The lesion may have an irregular surface, ulceration, or crusting. The size of the lesion may vary from a few millimeters to several centimeters.
- Histopathology: Histopathology is the gold standard for the diagnosis of malignant pilomatricoma. The characteristic histological features of malignant pilomatricoma include a large, pleomorphic, and atypical basaloid cell population with a high mitotic rate and frequent areas of necrosis. Additionally, the tumor may invade into the surrounding dermis or subcutaneous tissue.
- Immunohistochemistry: Immunohistochemistry can aid in the diagnosis of malignant pilomatricoma by detecting the expression of specific markers such as CK20, P53, and Ki-67. CK20 is a keratin marker that is expressed in the hair follicle matrix, and its expression is lost in malignant pilomatricoma. P53 is a tumor suppressor protein that is often overexpressed in malignant tumors. Ki-67 is a marker of cell proliferation that is frequently expressed in malignant tumors.
- Electron microscopy: Electron microscopy can provide ultrastructural details of malignant pilomatricoma. The tumor cells have a characteristic basaloid appearance with numerous cytoplasmic tonofilaments, which are indicative of their hair follicle origin.
- CT scan: CT scan can be used to evaluate the extent of local invasion and the presence of regional or distant metastases. CT scan may reveal irregular margins, heterogeneous enhancement, and areas of necrosis within the tumor.
- MRI: MRI can provide better soft tissue contrast than CT scan and can be used to evaluate the extent of local invasion and the presence of regional or distant metastases. MRI may reveal heterogeneous signal intensity, irregular margins, and areas of necrosis within the tumor.
- PET scan: PET scan can be used to detect the metabolic activity of the tumor and to identify regional or distant metastases. PET scan may reveal increased uptake of glucose within the tumor and in metastatic lesions.
- Ultrasonography: Ultrasonography can be used to evaluate the size and extent of the tumor and to assess the presence of regional lymph node involvement. Ultrasonography may reveal a hypoechoic mass with irregular margins and posterior acoustic shadowing.
- Fine-needle aspiration cytology: Fine-needle aspiration cytology can be used to obtain a tissue sample from the tumor for histological evaluation. However, it is often challenging to diagnose malignant pilomatricoma using fine-needle aspiration cytology due to its cytological similarity with other malignant skin tumors.
- Punch biopsy: Punch biopsy can be used to obtain a tissue sample from the tumor for histological evaluation. However, it may not provide enough tissue for accurate histological evaluation.
- Excisional biopsy: Excisional biopsy is the preferred method for obtaining a tissue sample from the tumor for histological evaluation. It provides enough tissue for accurate histological evaluation and can also be curative if the tumor
Treatment
The treatment of malignant pilomatricoma depends on various factors such as the size and location of the tumor, the stage of the disease, and the patient’s overall health. In this article, we will discuss treatment options for malignant pilomatricoma in detail.
Non Pharmacological treatment
- Surgery: The primary treatment for malignant pilomatricoma is surgery, which involves removing the tumor and surrounding tissue. The extent of surgery depends on the size and location of the tumor. If the tumor is small, it may be removed with a margin of normal tissue. If the tumor is large or has spread to nearby lymph nodes, a more extensive surgery may be required.
- Radiation therapy: Radiation therapy uses high-energy X-rays to kill cancer cells. It is typically used after surgery to kill any remaining cancer cells and reduce the risk of recurrence. Radiation therapy may also be used as a primary treatment for tumors that cannot be surgically removed.
- Chemotherapy: Chemotherapy involves using drugs to kill cancer cells. It is typically used for advanced or metastatic malignant pilomatricoma. The drugs may be given orally or intravenously.
- Immunotherapy: Immunotherapy uses the body’s immune system to fight cancer. It is a newer form of cancer treatment that has shown promising results in various cancers, including malignant pilomatricoma.
- Targeted therapy: Targeted therapy uses drugs that target specific molecules that are involved in the growth and spread of cancer cells. It is a newer form of cancer treatment that has shown promising results in various cancers, including malignant pilomatricoma.
- Cryotherapy: Cryotherapy involves freezing the tumor with liquid nitrogen to kill cancer cells. It is typically used for small tumors that are located on the skin surface.
- Mohs surgery: Mohs surgery is a specialized surgical technique that is used to remove skin tumors with minimal damage to surrounding tissue. It is typically used for tumors that are located on the face, scalp, or other areas where preserving normal tissue is important.
- Photodynamic therapy: Photodynamic therapy involves using a special light and a photosensitizing agent to kill cancer cells. It is typically used for tumors that are located on the skin surface.
- Laser therapy: Laser therapy involves using a high-energy beam of light to kill cancer cells. It is typically used for tumors that are located on the skin surface.
- Electrochemotherapy: Electrochemotherapy involves using electrical pulses to enhance the uptake of chemotherapy drugs by cancer cells. It is typically used for tumors that are located on the skin surface.
- Immunomodulators: Immunomodulators are drugs that can stimulate or suppress the immune system. They may be used in combination with other treatments to enhance their effectiveness.
- Interferon therapy: Interferon therapy involves using a type of protein that is naturally produced by the body to fight cancer cells. It is typically used for advanced or metastatic malignant pilomatricoma.
- Radiofrequency ablation: Radiofrequency ablation involves using a special needle that emits high-frequency energy to heat and destroy cancer cells. It is typically used for tumors that are located deep within the skin.
- Photothermal therapy: Photothermal therapy involves using a laser to heat cancer cells and kill them. It is typically used for tumors that are located deep within the skin.
Medications
Drugs used for the treatment of malignant pilomatricoma, their mechanisms of action, and clinical applications.
- Methotrexate: Methotrexate is a chemotherapy drug that inhibits DNA synthesis by blocking the activity of dihydrofolate reductase. It is commonly used in the treatment of various types of cancer, including malignant pilomatricoma. Methotrexate is usually given as an intravenous infusion or injection, and its side effects include bone marrow suppression, liver toxicity, and gastrointestinal problems.
- Cisplatin: Cisplatin is a chemotherapy drug that works by cross-linking DNA strands, leading to cell death. It is commonly used in the treatment of various types of cancer, including malignant pilomatricoma. Cisplatin is usually given as an intravenous infusion, and its side effects include nephrotoxicity, ototoxicity, and neuropathy.
- Carboplatin: Carboplatin is a chemotherapy drug that works by inhibiting DNA synthesis. It is commonly used in the treatment of various types of cancer, including malignant pilomatricoma. Carboplatin is usually given as an intravenous infusion, and its side effects include bone marrow suppression, nausea, and vomiting.
- Doxorubicin: Doxorubicin is a chemotherapy drug that works by intercalating DNA strands, leading to cell death. It is commonly used in the treatment of various types of cancer, including malignant pilomatricoma. Doxorubicin is usually given as an intravenous infusion, and its side effects include bone marrow suppression, cardiotoxicity, and gastrointestinal problems.
- Etoposide: Etoposide is a chemotherapy drug that works by inhibiting topoisomerase II, leading to DNA strand breaks and cell death. It is commonly used in the treatment of various types of cancer, including malignant pilomatricoma. Etoposide is usually given as an intravenous infusion, and its side effects include bone marrow suppression, nausea, and vomiting.
- Vinblastine: Vinblastine is a chemotherapy drug that works by inhibiting microtubule formation, leading to cell cycle arrest and cell death. It is commonly used in the treatment of various types of cancer, including malignant pilomatricoma. Vinblastine is usually given as an intravenous infusion, and its side effects include bone marrow suppression, nausea, and vomiting.
- Vincristine: Vincristine is a chemotherapy drug that works by inhibiting microtubule formation, leading to cell cycle arrest and cell death. It is commonly used in the treatment of various types of cancer, including malignant pilomatricoma. Vincristine is usually given as an intravenous infusion, and its side effects include neuropathy, constipation, and nausea.
- Paclitaxel: Paclitaxel is a chemotherapy drug that works by stabilizing microtubules, leading to cell cycle arrest and cell death. It is commonly used in the treatment of various types of cancer, including malignant pilomatricoma. Paclitaxel is usually given as an intravenous infusion, and its side effects include bone marrow suppression, neuropathy,
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