dermatologic disorders
Melanoma
Diagnosis of Melanoma
Biopsy Polarized light and immersion contact dermoscopy may be useful for distinguishing melanomas from benign lesions. However, biopsy and histologic evaluation should be considered if moles have certain characteristics of concern (known as the ABCDEs of melanoma): A: Asymmetry—asymmetric appearance B: Borders—irregular borders (ie, not round or oval) C: Color—color variation within the mole, unusual colors, or a color significantly different or darker than the patient's other moles D: Diameter—> 6 mm E: Evolution—a new mole in a patient > 30 years of age or a changing mole Patients at risk can be taught self-examination to detect changes in existing moles and to recognize features suggesting melanoma. Other red flags include Recent enlargement or change in shape Change in surface characteristics or consistency Signs of inflammation in surrounding skin, with possible bleeding, ulceration, itching, or tenderness However, recent enlargement, darkening, ulceration, or bleeding usually indicates that the melanoma has already invaded the skin deeply. If doubt exists, biopsy should include the full depth of the dermis and extend slightly beyond the edges of the lesion. Because earlier diagnosis can be lifesaving and features of melanoma can be variable, even slightly suspect lesions should be biopsied. Earlier diagnosis of melanoma is possible if biopsy specimens can be obtained from lesions having variegated colors (eg, brown or black with shades of red, gray, or blue), irregular elevations that are visible or palpable, and borders with angular indentations or notches. Biopsy should be excisional for most lesions except those on anatomically sensitive or cosmetically important areas; in these cases, a broad shave biopsy can be done. For broader lesions such as lentigo maligna, representative shave biopsies from several areas can increase the diagnostic yield. By doing step sections, the pathologist can determine the maximal thickness of the melanoma. Definitive radical surgery should not precede histologic diagnosis. Tumors, particularly if metastatic, are sometimes tested genetically for mutations, eg, to suggest treatment withvemurafenib, aBRAFinhibitor, for metastatic melanomas bearing a V600 mutation in theBRAFgene. includes Basal Cell Carcinoma and The staging of melanoma is based on clinical and pathologic criteria and closely corresponds to the traditional tumor-node-metastasis (TNM) classification system. The staging system classifies melanomas based on local, regional, or distant disease: Stages I and II: Localized primary melanoma Stage III: Metastasis to regional lymph nodes Stage IV: Distant metastatic disease Stage strongly correlates with survival. Sentinel lymph node biopsy (SLNB), a minimally invasive microstaging technique, is a major advance in the ability to stage cancers more accurately. Recommended staging studies depend on the Breslow depth (how deeply tumor cells have invaded) and histologic characteristics of the melanoma; ulceration indicates higher risk in melanomas that are < 0.8 mm Breslow depth (see table). Staging studies may include sentinel lymph node biopsy, laboratory tests (eg, complete blood count, lactate dehydrogenase, liver tests), chest x-ray, CT, and positron emission tomography (PET) and are done by a coordinated team that includes dermatologists, oncologists, general surgeons, plastic surgeons, and dermatopathologists. Stage Stage Thickness Thickness Ulceration Status Ulceration Status 0 Intraepithelial or in situ melanoma Not applicable IA < 0.8 mm Without ulceration IB < 0.8 mm With ulceration 0.8–1.0 mm With or without ulceration IIA > 1.0–2.0 mm Without ulceration IIB > 1.0–2.0 mm With ulceration IIIA > 2.0–4.0 mm Without ulceration IIIB > 2.0–4.0 mm With ulceration IVA >4.0 mm Without ulceration IVB >4.0 mm With ulceration Data fromKeung EZ, Gershenwald JE: The eighth edition American Joint Committee on Cancer (AJCC) melanoma staging system: implications for melanoma treatment and care.Expert Rev Anticancer Ther18(8):775-784, 2018. doi: 10.1080/14737140.2018.1489246 