MELANOCYTIC HYPERPLASIA IN SCARS - A HISTOPATHOLOGICAL INVESTIGATION OF 722 CASES

We studied 722 reexcision scars of benign and malignant lesions (excep t melanocytic lesions) excised over a 24-month period. The formalin-fi xed, paraffin-embedded tissue sections were examined histologically an d immunohistochemically. The histological features of melanocytic hype rplasia were present in 59 cases (8%), 56 from the sun-exposed skin of the face and neck and three from the trunk [p < 0.00001]. The most co mmon sites were the nose and lower eyelids, but the forehead was also frequently involved. Of the 59 patients, 41 were women (p < 0.0001). B asal cell carcinoma was the most frequent original lesion in both sexe s (80%). No melanocytic hyperplasia was found in 663 cases (298 on the trunk and extremities and 365 on the head and neck). We have seen thi s reaction pattern following reexcision of melanocytic lesions as well . Thus, interpreting reexcision margins when lentigo maligna or simila r lesions are reexcised may be fraught with difficulty. It is importan t for pathologists and dermatopathologists to recognize this phenomeno n because histologically the presence of increased numbers of large me lanocytes could be misinterpreted as melanoma in situ.