Peripheral Nerve Sheath Tumors of the Eyelid Dermis: A Clinicopathologic and Immunohistochemical Analysis

To determine the incidences, clinical features, and detailed histopathologic and immunohistochemical findings of 10 peripheral nerve tumors (isolated neurofibromas, solitary circumscribed neuromas [SCNs], and schwannomas) localized to the eyelid dermis.

In this retrospective clinicopathologic study, clinical records and paraffin sections subjected to hematoxylin and eosin, Masson trichrome, periodic acid-Schiff, reticulin, and Alcian blue staining were critically reviewed from each case. Additional paraffin sections were immunoreacted for S100, neurofilament, CD34, epithelial membrane antigen (EMA), glucose transporter-1 (glut-1), and calretinin.

Ten patients with a median age of 57 years had solitary, small, flesh-colored papules, 70% at the eyelid margin. Microscopically, they were diagnosed either as a SCN or an isolated neurofibroma. SCN was diffusely S100-positive (and sometimes diffusely calretinin-positive) with myriad neurofilaments. Fascicles of cells were separated by CD34-positive septa, and the lesions were surrounded by a glut-1/EMA-positive capsule. Neurofibromas were calretinin-negative and had a moderate number of S100-positive cells, with widely scattered neurofilaments, many CD34-postive intermixed cells, and no capsule. No schwannomas were diagnosed.

Peripheral nerve tumors of the eyelid have a distinct clinical presentation at the eyelid margin. Careful histopathologic and immunohistochemical studies can reliably separate the entities in the categories of isolated neurofibroma, SCN, and schwannoma when the last occurs. These distinctions can have important systemic implications.