BACKGROUND: Cutaneous indeterminate cell histiocytosis is a rare @entity5 . Its varied histological presentation and rarity have limited efforts to determine its pathogenic relationship with other histiocytic lesions and possibly, its recognition. METHODS: We report on an unusual histologic pattern of indeterminate cell histiocytosis that @entity8790 . A battery of immunohistochemical stains and electron microscopy were performed to elucidate the phenotype of the "histiocytic" cells. Based on a review of the literature, reported cases of indeterminate cell histiocytosis are presented and the diagnostic differential of spindle-cell lesions is discussed. RESULTS: Spindling histiocytes were positive for @entity2281 and @entity4896 . The monocytic/macrophage marker, @entity469 , and the dendritic cell marker, @entity10911 , were negative. Electron microscopy failed to reveal Birbeck granules. CONCLUSIONS: Relatively few reports of indeterminate cell histiocytosis exist, some of which include discussion of potential overlaps with the non-X histiocytoses. Although the presence of prominent spindling in our case expanded the differential to include non-histiocytic disorders, the identified histiocytes unequivocally fulfilled the criteria of @entity2281 and @entity4896 positivity without demonstrable Birbeck granules.

Cutaneous indeterminate cell histiocytosis: a new spindle cell variant resembling XXXX .

@entity10911 :: ('1380', 'Gene') :: ['CD21'] @entity5 :: ('MESH:D009369', 'Disease') :: ['neoplastic disorder'] @entity469 :: ('968', 'Gene') :: ['CD68'] @entity8790 :: ('MESH:D054740', 'Disease') :: ['resembled follicular dendritic sarcoma'] @entity2281 :: ('6271', 'Gene') :: ['S-100'] @entity4896 :: ('909', 'Gene') :: ['CD1a']
@entity8790 :: (MESH:D054740,Disease) :: ['dendritic cell sarcoma']
