title: Botryoid-type embryonal rhabdomyosarcoma of liver in a young cat.
abstract: An unusual malignant mesenchymal tumor arising in the liver of a 2-year-old cat is described. Histologically, the tumor showed considerable variation in growth pattern, cellularity, and cell types. Phenotypical diversity was confirmed by immunohistochemistry, showing expression of desmin, vimentin, S-100, and neuron-specific enolase in various areas of the tumor. On the basis of histopathology, immunohistochemistry, electron microscopy, and gross morphology, the tumor was classified as botryoid-type embryonal rhabdomyosarcoma. Differential diagnosis included so-called undifferentiated (embryonal) sarcoma of the liver, a rare tumor of the pediatric age group in humans. Problems of tumor heterogeneity and differentiation in mesenchymal tumors are discussed.
authors.affiliation: Institute of Pathology, GSF-National Research Center for Environment and Health, Germering, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Minkus
authors.forename: M
authors.initials: M
authors.lastname: Hillemanns
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D002415:Cats; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D003893:Desmin / Q000032:analysis / Q000378:metabolism; D003937:Diagnosis, Differential; D007150:Immunohistochemistry; D008099:Liver / Q000737:chemistry / Q000196:embryology / Q000473:pathology; D008113:Liver Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000662:veterinary*; D008297:Male; D008854:Microscopy, Electron; D010641:Phenotype; D018233:Rhabdomyosarcoma, Embryonal / Q000737:chemistry / Q000175:diagnosis / Q000662:veterinary*; D009418:S100 Proteins / Q000032:analysis / Q000378:metabolism; D014746:Vimentin / Q000032:analysis / Q000378:metabolism
chemical_list: D003893:Desmin; D009418:S100 Proteins; D014746:Vimentin