Recurrent Melanocytic Nevus Versus Melanoma

Recurrent melanocytic nevi can be a clinical and histopathologic challenge for dermatologists and pathologists alike. They are not uncommon, and typically present on the backs of young women with a history of a preceding shave biopsy a few months to years prior. Fortunately, a number of characteristic histopathologic features allow for recognition of this entity: an orderly “trizonal” architecture of confluent junctional melanocytes overlying a centrally fibrotic dermis, surrounded by dermal nests of small nevus cells with benign maturation and immunostaining patterns. It is important to maintain a high index of suspicion for this diagnosis, which can resemble a melanoma in both clinical and histopathologic appearance, in order to reduce the morbidity associated with unnecessary procedures such as re-excision or destruction.