Sunmin Yim
Resident in Kangbuk Samsung Hospital, South Korea
Title: A Case of Inverted Type A (Clonal) Nevus
Biography
Biography: Sunmin Yim
Abstract
Inverted type A (clonal) nevus is a unusual type of melanocytic nevus. It contains pigmented nests of type A nevus cells in the depth of a banal. The nest is occasionally surrounded by type B or C nevus cells. Therefore, type A nevus cells are layered in deeper portion of nevus and Type B and C nevus cells are observed on superficial layers. An unusual presentation of inverted type A nevus have been rarely reported with superficial neurotization.
We described a case of a 68 year-old female complained of solitary, 0.4 cm-sized, dome shaped, brownish to skin-colored papule on the occiput. There was no pruritus or pain on the lesion. The excision biopsy was performed. The histology examination revealed clustered, swirling, epithelioid, type A nevus cells proliferation in the deep portion of perifollicular area. The dense, basophilic type B nevus cells were surrounding the nests of type A cells. Moreover, extensive neurotized type C nevus cells appeared in the upper dermis. No atypia and abnormal mitosis were observed. It could be diagnosed with inverted type A nevus based on the clinical and histological findings.