Review Question - QID 104230

Given this patient's risk for melanoma, the nevus should be evaluated via an excisional biopsy with 2-3mm margins. An excisional biopsy is recommended, as prognosis is based on the depth of tumor growth.

Skin lesions that are suspicious for melanoma should be completely excised via an excisional biopsy with both horizontal and vertical margins. This simultaneously allows for the best chance of detecting cancerous cells as well as determining tumor thickness. The patient's prognosis is most highly correlated with the degree of tumor penetration from the granular layer in the epidermis. The utility of further interventions such as lymph node biopsy and adjuvant chemotherapy is also influenced by depth measurement.

Goldstein and Goldstein discuss the risk factors for melanoma. The characteristics that carry the highest relative risk of melanoma include the presence of a changing mole, atypical nevus syndrome, the presence of a large congenital nevus, white race, and a history of melanoma before age 40. They also describe the common physical characteristics of melanoma, which include moles that are asymmetric, have irregular borders, have different colors or recent change is color, and have a diameter >6 mm.

Balch et al. describe the most recent staging of melanoma from the American Joint Committee on Cancer. In addition to tumor thickness, tumor mitotic rate, ulceration, satellite metastases, immunochemical detection of nodal metastases and number of nodal metastases all contribute to staging of disease.

Figure A is an example of a cutaneous melanoma. Note the irregular borders, numerous colors and large size of the lesion. Illustration A demonstrates an additional example of a melanoma. Note the asymmetry of the lesion with both a raised and flat portion as well as the numerous colors within the lesion.

Incorrect Answers:
Answer 1: Given this woman's sun exposure history and concerning physical features of the nevus, there is a high suspicion for melanoma. Therefore, tissue is needed to make a diagnosis and observation is inappropriate.
Answer 2: Shave biopsies are discouraged as the tissue obtained may be insufficient to determine the correct depth measurement.
Answer 4: This is a procedure used to treat cervical dysplasia. It is not used for the diagnosis or treatment of melanoma.
Answer 5: A punch biopsy may be used if the suspicion for melanoma is low, when the lesion is small enough to be completely removed by a punch biopsy, or when it is impractical to perform an excision. This patient's presentation does not meet these criteria.