Palisaded encapsulated neuroma (solitary circumscribed neuroma). A clinicopathologic and immunohistochemical study.

Although palisaded encapsulated neuroma was first described over 20 years ago, it has received little attention. We present the clinical, histopathologic, and immunohistochemical features of 10 cases of this entity. The cases were studied by routine light-microscopic examination and immunohistochemistry using the avidin-biotin-peroxidase technique. Clinical information and follow-up data were obtained from the hospital records. The lesions were solitary, asymptomatic, skin-colored papules that were located on the faces of patients who ranged in aged from 37 to 66 years (average, 52 years). The female to male ratio was 1:1. None of the patients had von Recklinghausen's disease, and none of the lesions recurred after excision. Histopathologically, the tumors were well circumscribed and situated predominantly in the dermis. They were encapsulated and composed of spindle cells arranged in interlacing fascicles. The tumor cells were positive for S-100 protein. The capsule was composed of flattened, elongated cells that showed positivity for epithelial membrane antigen (EMA).