title: Multinucleated floret-like giant cells in sporadic and NF1-associated neurofibromas: a clinicopathologic study of 94 cases.
abstract: Multinucleated floret-like giant cells (MNFGCs), similar to those commonly observed in pleomorphic lipoma and giant cell fibroblastoma, have been occasionally reported in gynecomastia and neurofibromas from patients affected by neurofibromatosis type 1 (NF1). Accordingly, it has been suggested that their detection, especially in an otherwise typical neurofibroma, could be a morphological clue to diagnosis of NF1. The aim of the present study was the identification of MNFGCs in a large series (94 cases) of sporadic and NF1-associated neurofibromas, to assess if their presence may indeed be a morphological marker of NF1. Numerous MNFGCs, namely, those that were easily apparent at low magnification (x50 and x100), were identified only in 5.3% of cases. In 18.1% of cases, a low number of these cells could be observed but only after a careful search, especially at higher magnification (x200 and x400). Immunohistochemically, all MNFGCs were stained with vimentin and CD34, but not with S-100 protein. Interestingly, there was no statistically significant correlation between MNFGCs (presence or absence) and NF1 (p = 0.73), gender (p = 0.59), age (p = 0.43), and site of tumor (cutaneous vs deep-seated soft tissue; p = 0.27). Our clinicopathologic findings suggest that MNFGCs in an otherwise typical neurofibroma are not a reliable marker of NF1, likely representing a morphological reactive change of the indigenous dermal or endoneurial fibroblasts or dendritic cells in response to unknown microenvironmental stimuli.
authors: Dipartimento G.F. Ingrassia, Policlinico Universitario G. Rodolico, Anatomia Patologica, Università di Catania, Via S. Sofia 87, Catania, Italy. g.magro@unict.it
authors: Gaetano
authors: G
authors: Magro
authors: Paolo
authors: P
authors: Amico
authors: Giada Maria
authors: GM
authors: Vecchio
authors: Rosario
authors: R
authors: Caltabiano
authors: Marine
authors: M
authors: Castaing
authors: Denisa
authors: D
authors: Kacerovska
authors: Dmitry V
authors: DV
authors: Kazakov
authors: Michal
authors: M
authors: Michal
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018952:Antigens, CD34 / Q000032:analysis; D002648:Child; D005260:Female; D015726:Giant Cells / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009455:Neurofibroma / Q000473:pathology*; D009456:Neurofibromatosis 1 / Q000473:pathology; D012189:Retrospective Studies; D009418:S100 Proteins / Q000032:analysis; D012878:Skin Neoplasms / Q000473:pathology*
chemical_list: D018952:Antigens, CD34; D009418:S100 Proteins