Skin is the most common site of malignant melanoma. A malignant melanoma may arise-
1. In a preexisting pigmented naevus, either in junctional naevus, compound naevus or in Hutchinson’s lentigo.
2. De novo in apparently normal skin.
Causes-
1. Patients of any age may develop malignant melanoma.
2. Women develop melanoma slightly more than men. Melanomas in women are more common in lower extremities. Women have a better prognosis than men with lesions.
3. It is more common in whites, who are more exposed to sunlight. It is more frequent in Australia.
4. Abnormalities in chromosomes 1, 6 and 9 have been noticed in malignant melanoma patients.
5. Palms, soles and external genitalia are common sites. It may also occur beneath the nail when it is called subungual melanoma. This is more often seen in the thumb or great toe. Melanoma may also be seen in choroid of the eye or even in meninges. Malignant melanoma is also noticed in the rectum and anal canal.
6. Steroid hormones may have influence to produce malignant melanoma.
Symptoms-
1. Long standing mole has suddenly shown rapid growth within last few days. Such increase in size occurs in all directions. The moles become wider and thicker.
2. The malignant mole becomes darker. Such color change is often patchy. Some areas may show increased vascularity.
3. The overlying epithelium becomes ulcerated and often breaks down with minor injury. This tends to bleed. These changes are particularly noticed when the growth has become malignant.
4. Malignant melanoma often itches. Sometimes patient complain of lymph node enlargement.
5. Only in late cases one may complain of weight loss, dyspnoea or jaundice.
6. Majority of melanomata are seen in the palms and soles of the feet.
7. It may be of any color from brown to black. More blackish is the color, more chance is there of malignancy.
8. When small, the surface may be smooth, but as it attains large size, ischemic necrosis, small ulcers, crusts etc, are seen on the surface. Bleeding is quite common on the surface and the surface of a big melanoma looks wet, soft and boggy.
9. Tumor feels firm. Small satellite nodules may feel hard.
Treatment-
1. Surgery.
2. Systemic chemotherapy.
3. Immunotherapy.
4. Radiotherapy.