Malignant Melanoma

INTRODUCTION Cutaneous malignant melanoma is an invasive proliferation of malignant melanocytes, and accounts for 1% of all eyelid malignancies. The incidence increases with age, but remains relatively stable from the fifth to the seventh decades. Cutaneous malignant melanoma may be classified into four different types: lentigo maligna melanoma (5%), superficial spreading melanoma (70%), nodular melanoma (16%), and acral lentiginous melanoma (9%). Nodular melanoma and lentigo maligna melanomas are the most common types affecting the eyelids. In all types, initially, a noninvasive horizontal growth phase occurs, which is followed by an invasive vertical growth phase. Changes in outline and color are features that tend to distinguish melanoma from benign pigmented lesions. Risk factors for the development of malignant melanoma include congenital and dysplastic nevi, changing cutaneous moles, excessive sun exposure and sun sensitivity, family history, age greater than 20 years, and Caucasian race. Patients with the dysplastic nevus syndrome (B-K mole syndrome) have a high risk of developing malignant melanoma. Prognosis and metastatic potential are linked to the depth of invasion and thickness of the tumor. Lesions less than 0.75 mm have a five-year survival rate of 98%, while those greater than 4 mm have a less than 50% survival rate. Additionally, malignant melanoma involving the eyelid margin has a poorer prognosis.

CLINICAL PRESENTATION Superficial spreading melanoma presents as a small, pigmented lesion with mild elevation and irregular borders. It may go through a phase of horizontal growth, in which the pigmentation extends in diameter, but eventually tends to become nodular and indurated, signifying invasive growth. Nodular melanoma may present as a markedly pigmented or amelanotic

Kaposi Sarcoma Flat Lesion

nodule that rapidly increases in size with associated ulceration and bleeding. Any lesion that develops hues of white, gray, blue, black, red, or pink is suspect. Variation in brown pigment especially if in an asymmetric fashion is suspicious. Other factors such as papule or nodule formation of a previously flat pigmented lesion, bleeding, ulceration, or loss of fine skin lines should raise concern for possible melanoma.

HISTOPATHOLOGY Superficial spreading malignant melanoma features a proliferation of atypical melanocytes, singly and in nests, within all levels of the epidermis. The atypical melanocytes may be confined to the epidermis (in situ melanoma) or they may be associated with tumor cells invading the dermis. The tumor cells may be epithelioid, nevus-cell like, or spindle-shaped. Nodular melanoma lacks an intraepidermal component of atypical melanocytes adjacent to the infiltrative tumor, but there is usually epidermal invasion by malignant cells directly over the tumor. Nodular malignant melanoma is commonly composed of round to oval epithelioid cells with varying amounts of melanin pigment.

Nevus Nevocellular Skin

DIFFERENTIAL DIAGNOSIS The differential diagnosis for malignant melanoma includes nonmalignant pigmented nevocellular nevi, pigmented basal cell carcinoma, pigmented seborrheic keratosis, dysplastic nevi, Kaposi's sarcoma and hemangioma.

TREATMENT The treatment of choice for cutaneous malignant melanoma of the eyelid is surgical excision with wide margins of 1 cm confirmed by histologic monitoring. Often, a 1 cm clear margin may not be possible. In such cases Mohs' micrographic surgery may be helpful, but some Moh's surgeons do not feel that frozen sections are accurate enough for melanomas. Regional lymph node dissection should be performed for tumors greater than 1.5 mm depth and/or for tumors that show evidence of vascular or lymphatic spread. A metastatic evaluation also is recommended for patients diagnosed with any malignant melanoma.

How To Prevent Skin Cancer

How To Prevent Skin Cancer

Complete Guide to Preventing Skin Cancer. We all know enough to fear the name, just as we do the words tumor and malignant. But apart from that, most of us know very little at all about cancer, especially skin cancer in itself. If I were to ask you to tell me about skin cancer right now, what would you say? Apart from the fact that its a cancer on the skin, that is.

Get My Free Ebook

Post a comment