title: Indeterminate cell histiocytosis: a rare histiocytic disorder.
abstract: A 64-year-old woman, otherwise healthy, presented with multiple reddish-brown, slightly yellowish papules on the face and neck, which had developed 3 years earlier. The lesions were painless and nonpruritic and varied in diameter from 1 to 5 mm. Histological and immunohistochemical examination of cutaneous biopsies revealed a diffuse dermal infiltrate composed mainly of histiocytes which expressed both Langerhans cell as well as monocytic/macrophages cell marker characteristics. Electron microscopic studies revealed no Birbeck granules within the cytoplasm of the neoplastic cells, leading to a diagnosis of indeterminate cell histiocytosis. Indeterminate cell histiocytosis is a very rare disease characterized by the proliferation of indeterminate histiocytes which morphologically and immunophenotypically resemble Langerhans cells but lack Birbeck granules.
authors.affiliation: Department of Dermatology, University of L'Aquila, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Manente
authors.forename: C
authors.initials: C
authors.lastname: Cotellessa
authors.forename: I
authors.initials: I
authors.lastname: Schmitt
authors.forename: K
authors.initials: K
authors.lastname: Peris
authors.forename: G
authors.initials: G
authors.lastname: Torlone
authors.forename: A O
authors.initials: AO
authors.lastname: Muda
authors.forename: M C
authors.initials: MC
authors.lastname: Romano
authors.forename: S
authors.initials: S
authors.lastname: Chementi
mesh_terms: D005260:Female; D015614:Histiocytosis / Q000473:pathology*; D006801:Humans; D008875:Middle Aged; D012867:Skin / Q000648:ultrastructure