title: Metastasis of a well-differentiated liposarcoma in a dog and a note on nomenclature of fatty tumours.
abstract: A slow-growing mass in the left thigh of a 7-year-old spayed female fox terrier dog was originally diagnosed as an infiltrative lipoma by surgical biopsy. Necropsy findings one year later revealed multiple masses made up of well-differentiated adipocytes in the spleen, liver, lungs and a lymph node. The final histopathological diagnosis of these masses and, in retrospect, for the initial leg mass was well-differentiated liposarcoma. This case illustrates some of the confusion in current nomenclature of fatty tumours. Tumours made up of well-differentiated adipose cells which show no tendency toward invasion of surrounding tissue should be designated lipomas. We suggest that fatty tumours characterized by local tissue invasion and/or metastasis should be classified as liposarcomas. Liposarcomas may be further subdivided into well-differentiated and poorly-differentiated types.
mesh_terms: D000818:Animals; D004283:Dog Diseases; D004285:Dogs; D005260:Female; D008080:Liposarcoma / Q000473:pathology / Q000662:veterinary*; D008113:Liver Neoplasms / Q000473:pathology / Q000662:veterinary; D008175:Lung Neoplasms / Q000556:secondary / Q000662:veterinary; D008207:Lymphatic Metastasis; D012983:Soft Tissue Neoplasms / Q000473:pathology / Q000662:veterinary*; D013160:Splenic Neoplasms / Q000473:pathology / Q000662:veterinary; D009626:Terminology as Topic