Solitary circumscribed neuroma of the skin (so-called palisaded, encapsulated neuroma). Clinicopathological analysis of three cases with emphasis on differential diagnosis

Abstract

Three cases of solitary circumscribed neuroma (so-called palisaded, encapsulated neuroma) arising in the dermis have been studied. Two patients were male and one was female, with ages ranging from 27 to 59 years. All lesions arose on the forehead. Histologically, the neoplasms were partly encapsulated and were composed of broad fascicles, nests, and whorl-like structures of bland appearing spindle cells often separated by artefactual clefts. Immunohistochemically, most of the tumour cells stained positive for S-100 protein, and a considerable number also for CD 34, but failed to stain for epithelial membrane antigen and melanoma associated antigens. Solitary circumscribed neuroma has to be distinguished from long-standing dermal melanocytic nevus, mucosal neuromas seen in type IIb multiple endocrine neoplasia (MEN) syndrome, classical and cellular schwannoma, neurofibroma, perineurioma, traumatic neuroma, and angioleiomyoma.