title: [Perineurioma].
abstract: Perineurioma (storiform perineurial fibroma) is a rarely diagnosed benign tumour of perineurial cells. Presented tumour occurred subcutaneously in the right thigh of a 53-year-old man. It was well limited and consisted of whirl like and concentric laminar bundles of spindle and oval cells in variable local density. A storiform pattern was not present. Cells with richer cytoplasm, bland nuclei and solitary intranuclear pseudoinclusions formed focal meningioma like structures. Differential diagnosis had to distinguish benign neuronal tumours, myxoid variant of dermatofibrosarcoma protuberans and especially a "low grade" fibromyxoid sarcoma. A relevant immunohistochemical marker of perineurioma (for differential diagnosis) was the expression of epithelial membrane antigen (EMA) with negativity of S-100 protein.
authors.affiliation: Oddelenie patológie NsP, Trencín.
authors.forename: M
authors.initials: M
authors.lastname: Zámecník
authors.forename: P
authors.initials: P
authors.lastname: Gomolcák
mesh_terms: D003937:Diagnosis, Differential; D005350:Fibroma / Q000473:pathology*; D006801:Humans; D007866:Leg / Q000294:innervation; D008297:Male; D008875:Middle Aged; D018317:Nerve Sheath Neoplasms / Q000473:pathology*; D010524:Peripheral Nervous System Neoplasms / Q000473:pathology*