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Page: Diagnosis
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Moles that are irregular in color or shape are suspicious of a malignant or a premalignant melanoma. Following a visual examination and a dermatoscopic exam (an instrument that illuminates a mole, revealing its underlying pigment and vascular network structure), the doctor may biopsy the suspicious mole. If it is malignant, the mole and an area around it needs excision. This may require a referral to a surgeon or dermatologist.
The diagnosis of melanoma requires experience, as early stages may look identical to harmless moles or not have any color at all. Where any doubt exists, the patient will be referred to a specialist dermatologist. Beyond this expert knowledge a biopsy performed under local anesthesia is often required to assist in making or confirming the diagnosis and in defining the severity of the melanoma.
Excisional biopsy is the management of choice; this is where the suspect lesion is totally removed with an adequate ellipse of surrounding skin and tissue. The biopsy will include the epidermal, dermal, and subcutaneous layers of the skin, enabling the histopathologist to determine the depth of penetration of the melanoma by microscopic examination. This is described by Clark's level (involvement of skin structures) and Breslow's depth (measured in millimeters).
If an excisional biopsy is not possible in certain larger pigmented lesions, a punch biopsy may by performed by a specialist hospital doctor, using a surgical punch (an instrument similar to a tiny cookie cutter with a handle, with an opening ranging in size from 1 to 6 mm). The punch is used to remove a plug of skin (down to the subcutaneous layer) from a portion of a large suspicious lesion, for histopathological examination.
Lactate dehydrogenase (LDH) tests are often used to screen for metastases, although many patients with metastases (even end-stage) have a normal LDH; extraordinarily high LDH often indicates metastatic spread of the disease to the liver. It is common for patients diagnosed with melanoma to have chest X-rays and an LDH test, and in some cases CT, MRI, PET and/or PET/CT scans. Although controversial, sentinel lymph node biopsies and examination of the lymph nodes are also performed in patients to assess spread to the lymph nodes.
Sometimes the skin lesion may bleed, itch, or ulcerate, although this is a very late sign. A slow-healing lesion should be watched closely, as that may be a sign of melanoma. Be aware also that in circumstances that are still poorly understood, melanomas may "regress" or spontaneously become smaller or invisible - however the malignancy is still present. Amelanotic (colorless or flesh-colored) melanomas do not have pigment and may not even be visible. Lentigo maligna, a superficial melanoma confined to the topmost layers of the skin (found primarily in older patients) is often described as a "stain" on the skin. Some patients with metastatic melanoma do not have an obvious detectable primary tumor.
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Important notice:
The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other
qualified health provider with any questions you may have regarding a medical condition.
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