Perineurioma: A Distinctive and Underrecognized Peripheral Nerve Sheath Neoplasm

Abstract

Context.—Perineuriomas are benign peripheral nerve sheath neoplasms composed of perineurial cells with characteristic immunohistochemical and ultrastructural features. They have been traditionally classified into two main types according to their location—intraneural and extraneural—and overlap histologically with many other tumors, which may be diagnostically challenging to general surgical pathologists. Objective.—To review the clinical, morphologic, immunohistochemical, ultrastructural, cytogenetic, and molecular genetic aspects of perineurioma, as well as to discuss its clinicopathologic variants and differential diagnosis. Data Sources.—English-language literature published between 1966 and 2005 was reviewed. Conclusions.—The correct identification of perineuriomas is important to avoid unnecessary overtreatment. The histologic diagnosis should be confirmed through immunohistochemical studies (including epithelial membrane antigen, S100 protein, and more recently described antibodies such as claudin-1 and GLUT1) or electron microscopy. Cytogenetic and molecular genetic studies are still of limited value for the diagnosis of perineuriomas but may play a fundamental role in excluding important differential diagnoses and also in helping elucidate the biology of these poorly known neoplasms.

Immunohistochemical Detection of CD34, E-cadherin, Claudin-1, Glucose Transporter 1, Laminin, and Protein Gene Product 9.5 in 28 Canine and 8 Feline Meningiomas

“…4,15 Zero to 13% of human hemangiopericytomas, another possible mimic of meningiomas, have low expression of claudin-1 15,43 ; however, it is expressed in most perineuriomas. 26 Based on our results with meningiomas and on results in the human literature with meningiomas and their mimics, claudin-1 immunohistochemistry has high specificity (if epithelial neoplasms are excluded) and low to moderate sensitivity for meningiomas. Additional studies with canine and feline mesenchymal neoplasms are necessary to evaluate the specificity of claudin-1 for meningioma.…”

“…Of 33 meningiomas, 31 (94%) expressed CD34 with a diffuse cytoplasmic or granular pattern in most neoplastic cells or multifocally (Figs. [23][24][25][26]. All feline meningiomas and all but 2 canine meningiomas (1 fibroblastic, 1 anaplastic) were positive.…”

Sclerosing perineurioma: case report and literature review

“…Consequently, this marker is useful for the differential diagnosis with dermatofibrosarcoma protuberans, fibromyxoid sarcoma, desmoplastic fibroblastoma, or fibromatosis [14]. Perineurioma is also characteristically positive for vimentin and there have been cases reported with positivity for cytokeratins, CAM 5.2, muscle-specific actin, collagen IV, laminin, GLUT-1, CD99, and CD34 [3,8,9,11,15]. In our patient, sclerosing perineurioma was positive for EMA and claudin-1, and negative for S100 protein.…”

“…Other body locations occasionally reported include the oral cavity [5,6] and scrotal region [7]. Two main variants have been identified: an extremely rare intraneural form and a more common extraneural or soft tissue variant [2,8]. A sclerosing extraneural variant was first described in 1997 [9]; since then less than 50 cases of this presentation have been documented [3,10].…”

Clinicoradiological features of intraneural perineuriomas obviate the need for tissue diagnosis

“…These tumors have a characteristic histopathological appearance with pseudo-onion bulb whorls of perineurial cells arranged around axons that may display varying degrees of degeneration. 4,8 A major advance in the diagnosis of intraneural perineuriomas was the advent of immunohistochemical staining for epithelial membrane antigen (EMA). Intraneural perineuriomas are positive for EMA and negative for the Schwann cell marker S100.…”