Uncommon presentation of an invasive T‐cell lymphoma in a young Warmblood stallion

A 2‐year‐old stallion was referred to the Department of Internal Medicine, Reproduction and Population Medicine of Ghent University with signs of lethargy and anorexia. Abdominal and thoracic ultrasound appeared normal. Biochemistry revealed severe liver dysfunction and haematology indicated a leucocytosis. Therefore, treatment with broad‐spectrum antimicrobials and supportive perfusion therapy was initiated. After a few days severe quidding was observed. Oral examination identified a suspected mass of the soft palate. Radiographs confirmed the presence of a soft tissue mass in the left maxillary sinuses. Due to cost constraints, computed tomography (CT) could not be performed. As the clinical condition deteriorated, the stallion was euthanised. Post‐mortem examination revealed an unusual, multicentric T‐cell lymphoma, characterised by a primary, bilaterally symmetrical, severely invasive mass in the head with metastases in numerous lymph nodes and multiple thoracic and abdominal organs.