Localized histiocytic sarcoma in a dog: an uncommon diagnosis in forelimb lameness

Abstract

SummaryThe clinical, ultrasonographic, arthrographic and histopathological aspects of a localized histiocytic sarcoma in the tendon sheath of the biceps brachii muscle in a Flat-Coated Retriever are described. An eight-year-old female Flat-Coated Retriever was referred for evaluation of chronic forelimb lameness. The orthopaedic examination revealed a painful shoulder joint. Ultrasonographic evaluation revealed distention of the tendon sheath of the biceps brachii muscle and the presence of multiple, hyperechoic structures in the distal portion of the sheath. The histological and immunohistochemical diagnosis of a biopsy taken during surgical exploration of the shoulder joint was histiocytic sarcoma. Palliative treatment with corticosteroids was administered but the dog was euthanized at the owner’s request four months following diagnosis due to progressing lameness. Post-mortem examination confirmed the diagnosis of histiocytic sarcoma without any evidence of metastases.