Synovial cell sarcoma in a dog: A misnomer-Cytologic and histologic findings and review of the literature

Imaging features of benign synovial inflammation affecting the long digital extensor tendon sheath in a dog

A dog was evaluated for right pelvic limb lameness. Computed tomography and magnetic resonance imaging revealed an irregular, contrast-enhancing mass extending along the proximolateral right tibia, involving the long digital extensor tendon (LDET) ± cranial tibialis muscle. Pulmonary nodules, nonspecific hepatomegaly, and splenic nodules were also present. The primary differential diagnosis was soft tissue neoplasia. Surgical biopsy with histopathology revealed benign, chronic inflammation, and fibrosis. Idiopathic synovial inflammation should be included as a differential diagnosis for dogs with this combination of clinical and imaging characteristics.

Common Neoplastic Diseases Affecting the Forelimb

Lameness, new swelling, or mass occurrence are the most common reasons for presentation when neoplasia affects the limbs. Tumors of the skin or subcutaneous tissues, joints, muscles, bones, or digits of the forelimb are reported. Diagnosis with fine needle aspiration or biopsy is necessary before treatment to allow staging, planning of treatment, and prognostication. The planning of surgical treatment of limb tumors is essential to maximize the chance of a complete resection on the first surgery, given that less skin is available for primary closure in subsequent revision or recurrence surgeries.