Malignant paravertebral sarcoma with concurrent hepatic metastases in a corn snake (Pantherophis guttatus)

Vertebral disease is a common disorder in snakes. Although musculoskeletal neoplasms have been reported as the cause of vertebral disease, they are rare tumors in snakes. This case report describes a spindle cell sarcoma affecting the vertebral and paravertebral tissues with metastases in the liver. A 14-year-old, male corn snake (Pantherophis guttatus) was presented with progressive swelling of the dorsal body region of the middle third of the snake persisting for three weeks. In addition, the snake had been anorexic for three months and had shown progressively generalised lethargy and episodes of ataxia for four months. Physical examination revealed an approximately 15 × 2.5 × 1.5 cm firm and nodular mass lesion dorsal to the vertebral column. Additionally, a firm intracoelomic mass was palpable in the corresponding body region. The snake exhibited flaccid muscle tone and poor body condition, characterised by concave muscle contours. Dorsoventral and lateral survey radiographs showed irregular bone shape consistent with osteophyte formation and bone remodeling, segmented vertebral fusion, and lysis of vertebral processes. Furthermore, a well-demarcated intracoelomic mass with soft-tissue opacity was determined ventrally to the (para)vertebral alterations. Ultrasonographically, the intracoelomic mass was presented as an irregularly structured, moderately vascularized liver-associated lesion. Due to the severely reduced overall condition and the advanced stage of the (para)vertebral disease leading to a poor to grave prognosis, the animal was euthanized. Histopathology revealed a spindle cell sarcoma within the vertebrae and adjacent musculature with metastases in the liver. The present case highlights neoplastic disease as an important differential diagnosis for common vertebral disorders in snakes. Also, the report emphasizes the potential of metastatic spread in reptiles.