Subungual Melanocytic Lesions: A Histopathological Review

In a study of subungual melanocytic lesions, Dong-Youn Lee reviewed histopathology slides, clinical records, and photographs of 23 cases of subungual melanoma. Subungual melanoma, a rare type of melanoma that originates from the nail matrix, traditionally led to amputation due to its poor prognosis and the short distance from the matrix to the bone. However, the study found that dermal invasion in the nail matrix area tends to occur later than in other areas of the nail unit, suggesting that conservative surgery might be justified for early subungual melanoma. Out of the 23 cases, 5 were melanoma in situ, 18 showed dermal invasion, but none had invasion in the nail matrix area only. The nail matrix area generally showed thinner dermal invasion compared to other areas. These findings indicate that the nail matrix area is more resistant to invasion, and longitudinal incisional biopsy is necessary for accurate evaluation of melanoma invasion.