Melanoma is a cancer of melanin producing cells, melanocytes which are commonly found in skin. They are also present in eye and bowel. It is a rare but serious type of cancer. Most of the skin cancer associated deaths are caused due to melanoma. There are several types of melanoma.
The exact cause of melanoma is not known. Ultraviolet light (UV) is differentiated on the basis of wavelength in types A (UVA), B (UVB) and C (UVC). Ultraviolet light of type B (UVB) causes harmful changes in DNA of melanocytes.
Excessive exposure to ultraviolet light and sun light are the risk factors for melanoma. Melanoma can also occur in the areas of body having very less or no exposure to sun light. Besides this fair skin, history of sunburns, moles, excessive exposure to sun light, sunny or high attitude climates, family history of melanoma, exposure to carcinogens, presence of rare genetic disorders and weak immune system are the risk factors for melanoma.
Symptoms of melanoma are asymmetrical skin lesion with irregular borders, multiple colors, more than 6mm in diameter and they are enlarging or evolving. Changes in existing moles like itching, scaliness, change in texture of lump like hard or lump, pigment spread into the adjacent skin and oozing or bleeding of the mole are the symptoms of mole becoming cancerous.
Visual examination, dermatoscopic examination and microscopic examination of skin biopsy are the tests used for the diagnosis of melanoma. Lactate dehydrogenase, CT scan (Computerized Tomography), MRI (Magnetic resonance Imaging and PET (Positron Emission tomography) are the tests used for detection of metastasis of melanoma.
Complete skin examination after the age of 40 years for high risk people has been recommended.
Treatment of melanoma is surgery, adjuvant therapy, chemotherapy, radiotherapy and immunotherapy. High risk melanomas are treated with adjuvant therapy. The treatment depends on the stage of the cancer, age of the patient and personal preferences. Melanomas in early stage are removed surgically. Chemotherapy is generally given in advanced cases. Radiation therapy is generally used for metastasized cancer for symptomatic relief.
Prognosis of melanoma depends upon several factors like type of melanoma, location, presence of satellite lesions, depth of the lesion, regional or distant metastasis or presence of ulceration. If the cancer has distant metastasis then the prognosis is worse. Cancer metastasized to skin and lungs have better prognosis than to brain, liver and bones.
There may be itching, bleeding or ulceration of the melanoma lesion. Nausea, vomiting and poor appetite are the complications of metastasized melanoma.
