Excisional biopsy in melanoma

A 42-year-old female presents with the lesion (shown below) on the back of her calf. She has no significant medical problems and otherwise feels well. The lesion has not bled, but seems to have grown over the last few months. Appropriate initial management of this skin lesion should be??

• A) observation and removal if bleeding or further change occurs
• B) complete excision with normal margins
• C) complete excision with wide margins
• D) shave biopsy
• E) electrodessication and curettage

The answer is B. (Complete excision with normal margins) Even in the hands of experienced dermatologists, there is an approximately 15% false negative rate in determining the presence of melanoma based on examination alone; therefore, histologic confirmation is essential for both tumor diagnosis and staging. A complete excision with normal skin margins is preferable when possible as the first diagnostic step (e.g., excisional biopsy).
An incisional biopsy can be performed for larger lesions when complete excision is not practical and when the suspicion of melanoma is low; incisional biopsy does not adversely affect survival. Shave biopsies should be avoided because they may not provide enough tissue for diagnosis and do not allow for accurate depth measurement. All biopsies of lesions suspected of being melanomas should provide a piece of full-thickness skin extending to the subcutaneous fat.

When considering the diagnosis of melanoma, shave biopsies should be avoided because they may not provide enough tissue for diagnosis and do not allow for accurate depth measurement. All biopsies of lesions suspected of being melanomas should provide a piece of full-thickness skin extending to the subcutaneous fat.