A histopathologic study of congential melanocytic nevi

Cho, kwang Hyun; Chun, Ho Su; Kim, Seon Hoon; Park, Kyung Chan; Kim, Kyu Han; Lee, Seung Chul; CHil, Je Geun

Abstract

BACKGROUND: since congenital nevi may not always be identified clirically, it remains a challange for histologists to separate an acquired from a congehital nevus. The camparative histologic feature of congenital and acquired lesions have been described by several authors.
OBJECTIVE
In an attempt to establish reliable microscopic recognition of congenital nevi, the histologic features of 52 congenital melanocytic nevi were studied. MATERIAL AND METHODS: By reviewing HMB slides, histologic paterns were observed depending on the extent of nevus cell infiltration. An immunohistochemical study wi h anti S-100 protein and HMB-45 antibody was also performed.
RESULTS
Diffuse infiltratien of upper and lower dermis with nevu. cells was observed in 21 cases (40.0%). Nevus cell infiltration of appendages and neurovascular structures was observed in 29 cases (55.8%). Indian filing of dermal nevus cells was observed in 33 casesl(64.7%). Epidermis showed elongation of rete ridges in 36 ca.es(69.2%). Immunohistochemical staining with HMB 45 showed a positive raction in 9 cases out of 51 having dermal nevus cells, and epidemal melanocytes showed positive reaction in 20 cases.
CONCLUSION
Congenital melanocytie nevi can be classified by histolcgic appearance into several patterns. Nevus cells had a trend to infiltrate into the deeper dermis as the clinieal size increrased. Nevus cell infiltration of appendages and neurovascular structure was a common finding in congenital melanocytic nevi.