title: Hybrid schwannoma/perineurioma: a report of two cases including a possible radiation-induced case.
abstract: Hybrid schwannoma/perineurioma represents a recently characterized dermal or subdermal tumor showing schwannian cytomorphology and a perineurioma-like architecture composed of an admixture of both cell types. We report two additional cases of hybrid schwannoma/ perineurioma, one of which occurred after irradiation. Patient 1 was that of a 33-year-old man presented with a 2.8-cm dermal tumor on his left lower leg. Patient 2 was that of an 89-year-old woman with a history of uterine carcinoma treated by surgery and radiation therapy at the age of 35. She presented with a 1.2 × 1.0 cm dermal tumor on her left mons pubis with multiple coincidental basal-cell carcinomas around it. Both tumors were microscopically well circumscribed but unencapsulated and situated in the dermis and adipose tissue and showed a vague storiform and lamellar pattern. Cytologically, both tumors contained two-cell populations, i.e. spindled cells with plump nuclei, which were positive for S-100 protein and negative for epithelial membrane antigen (EMA), claudin-1 and CD34, as well as cells with very slender nuclei and elongated cytoplasmic processes, which were negative for S-100 protein yet expressed EMA, claudin-1 and CD34. Claudin-1 was a better marker to highlight cells with very slender nuclei than EMA. Both tumors lacked expression of neurofilament.
authors.affiliation: Department of Dermatology, Ikeda Municipal Hospital, Jonan, Ikeda, Osaka, Japan. bboohay02@ybb.ne.jp
authors.forename: Chika
authors.initials: C
authors.lastname: Ohata
authors.forename: Naho
authors.initials: N
authors.lastname: Imai
authors.forename: Haruna
authors.initials: H
authors.lastname: Hinogami
authors.forename: Kana
authors.initials: K
authors.lastname: Akamatsu
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Sumimura
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002280:Basal Cell Carcinoma / Q000378:metabolism / Q000473:pathology; D002467:Cell Nucleus / Q000473:pathology; D048430:Cell Shape; D020405:Dermis / Q000378:metabolism / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D009381:Neoplasms, Radiation-Induced / Q000378:metabolism / Q000473:pathology; D018317:Nerve Sheath Neoplasms / Q000378:metabolism / Q000473:pathology; D009442:Neurilemmoma / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology; D050151:Subcutaneous Fat / Q000378:metabolism / Q000473:pathology; D014594:Uterine Neoplasms / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy
chemical_list: D014408:Biomarkers, Tumor