title: T-cell signet-ring cell proliferation in the skin simulating true histiocytic lymphoma.
abstract: We report the case of a solitary ulcerating lesion on the elbow of a 32-year-old man. Routine histopathological examination strongly suggested a histiocytic malignancy. However, electron-microscopical, enzyme-cytochemical, and immunological studies revealed that the "tumor" cells were T lymphocytes with an unusual (Leu 1+, Leu 3a+, Leu 4+, Leu 5b+, OKT4+, HLA-DR+, Ki-1+, Leu MI+) immunological phenotype and an even more uncommon morphology characterized by the development of giant multivesicular bodies giving some cells a signet-ring cell appearance, and autophagocytosis. The lesion healed spontaneously, notwithstanding its malignant histology.
authors.affiliation: Institute of Pathology, University of Utrecht, The Netherlands.
authors.forename: S C
authors.initials: SC
authors.lastname: van der Putte
authors.forename: J
authors.initials: J
authors.lastname: Toonstra
authors.forename: H M
authors.initials: HM
authors.lastname: Bruns
authors.forename: D F
authors.initials: DF
authors.lastname: van Wichen
authors.forename: J A
authors.initials: JA
authors.lastname: van Unnik
authors.forename: W A
authors.initials: WA
authors.lastname: van Vloten
mesh_terms: D000328:Adult; D002455:Cell Division; D002467:Cell Nucleus / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D003937:Diagnosis, Differential; D004550:Elbow / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology*; D008297:Male; D008855:Microscopy, Electron, Scanning; D012871:Skin Diseases / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*; D013601:T-Lymphocytes / Q000473:pathology*