Cutaneous Pseudoglandular Schwannoma: A Case Report of an Unusual Histopathologic Variant

Multiple morphologic variants of schwannomas have been described, including plexiform, cellular, epithelioid, ancient, and glandular schwannomas. Very rare variants of schwannoma contain gland-like structures formed by neoplastic Schwann cells. The differential diagnosis in these cases can be challenging and includes adnexal neoplasms, neurothekeoma, and vascular neoplasms. We present a case of a well-circumscribed dermal-based neoplasm, which consisted of microcystic gland-like spaces lined by flat to cuboidal cells. A small focus of spindle cells with features resembling that of the Antoni A area typical of schwannoma was present. By immunohistochemistry, the cells lining the cystic spaces and the rest of the tumor were consistent with Schwann cells. In conjunction with this case report, we shall review the concept of the glandular structures in schwannoma.