Ultrastructural identification of a benign perineurial cell tumor

Abstract

A solitary tumor which by light microscopy was classified as a neurofibroma was found by electron microscopic study to be composed of parallel, elongate cells with collagen rich intervening matrix. The cells showed thin, polar cytoplasmic processes which extended long distances, frequent junctional complexes between cell processes, numerous surface vesicles, and either no or fragmented and variable basement membrane. Perineurial cells from small peripheral nerves of skin were demonstrated to have similar morphologic characteristics as the tumor cells. The present study, together with previous ultrastructural findings, indicate that benign peripheral nerve sheath tumors should be placed in at least three categories: Schwannoma, neurofibroma and perineurioma.

Extraneural Sclerosing Perineurioma of the Buccal Mucosa: A Case Report and Clinicopathologic Review

“…Variable immunoreactivity has been demonstrated for cytokeratin cocktail (including AE1, AE3, and CK1), CAM 5.2, claudin-1, muscle specific actin, alpha smooth muscle actin, laminin, and CD99 [9]. Ultrastructurally, lesional cells are notable for thin and widely separated bipolar cytoplasmic processes, [29] discontinuous external lamina, abundant pinocytotic vesicles, and tight junctions [1,2,26,37]. Although perineuriomas typically follow a benign course, in rare instances perineurial features have been described in malignant peripheral nerve sheath tumors [38,39].…”

“…Originally described on the basis of ultrastructural studies by Lazarus and Trombetta in 1978, [1] the perineurioma is an infrequently encountered benign peripheral nerve-sheath lesion arising from perineurial cells [2]. Typically divided into either the intraneural or the extraneural (soft tissue) variants, the perineurioma is thought to represent a clonal proliferation of perineurial cells that surround the periphery of nerve fascicles.…”

Perineurioma esclerosante: relato de caso e revisão da literatura

“…2 Lazarus e Trombetta relataram os achados de uma neoplasia de parte mole excisada do músculo gastrocnêmio de um homem de 45 anos, que foi originalmente diagnosticado como neurofibroma nos cortes corados pela hematoxilina e eosina. Por meio de estudos ultraestruturais, os autores provaram que essa neoplasia consistia em um perineurioma e definiram critérios de diferenciação perineural aplicáveis às células normais e às patológicas.…”

Ileal perineurioma as a cause of intussusception

“…The neoplastic cells comprising perineuriomas resemble those of the normal perineurium. These neoplasms were first described by Lazarus and Trombetta in 1978. 1 An unusual variant of soft-tissue perineurioma has been characterized by Fetsch and Miettinen as a sclerosing variant.…”

“…These neoplasms were first described by Lazarus and Trombetta in 1978. 1 An unusual variant of soft-tissue perineurioma has been characterized by Fetsch and Miettinen as a sclerosing variant. 2 Perineuriomas have also been reported in unusual locations such as the kidneys 3 and the paratesticular region.…”