title: Epithelioid perineurioma: an unusual variant.
abstract: An unusual epithelioid variant of perineurioma of the groin occurring in a 53-year-old man is described. The lesion appeared to be associated with a femoral nerve branch. The tumour was characterised by the presence of a syncytial proliferation of epithelioid cells, mimicking a meningioma of syncytial type. In addition there was a minor component of a conventional perineurioma. The tumour cells were EMA+, claudin-1+ and collagen type IV+. Bcl 2 was focally expressed. This case highlights the possibility of a common histogenetic pathway for meningiomas and perineuriomas. Although ultrastructural evidence of possible meningiomatous differentiation within an otherwise histologically typical perineurioma has been described, this is the first reported case of an unconventional epithelioid variant of perineurioma, histologically resembling meningioma.
authors.affiliation: Department of Histopathology, Nottingham University Hospitals NHS Trust, Nottingham, UK.
authors.forename: S A
authors.initials: SA
authors.lastname: Haider
authors.forename: R J
authors.initials: RJ
authors.lastname: Lemberger
authors.forename: C
authors.initials: C
authors.lastname: Fisher
authors.forename: T A
authors.initials: TA
authors.lastname: McCulloch
mesh_terms: D062445:Claudin-1; D024141:Collagen Type IV / Q000032:analysis; D015622:Epithelioid Cells / Q000473:pathology*; D005267:Femoral Nerve; D020428:Femoral Neuropathy / Q000473:pathology* / Q000601:surgery; D006119:Groin; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000032:analysis; D008875:Middle Aged; D018396:Mucin-1 / Q000032:analysis; D018317:Nerve Sheath Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D010524:Peripheral Nervous System Neoplasms / Q000473:pathology* / Q000601:surgery
chemical_list: C568108:CLDN1 protein, human; D062445:Claudin-1; D024141:Collagen Type IV; D008565:Membrane Proteins; D018396:Mucin-1