Diagnosis and Management of Pericardial Mesothelioma in a Leopard Gecko (<i>Eublepharus macularius</i>)

A 17-year-old male intact leopard gecko (Eublepharus macularius) was presented for lethargy, distended abdomen, and rapid weight loss. Palpation revealed ascites and subcutaneous edema in the axillary region bilaterally. Coelomic ultrasonography revealed a large (19 × 14 × 14 mm), focal, irregularly marginated heterogeneous cavitated mass associated with the right side of the heart. There was also a large volume of echogenic pericardial effusion, causing severe distension of the pericardial space. A small volume of anechoic coelomic effusion was detected in addition to mild diffuse hepatomegaly. Neoplasia (cardiac or pericardial) was considered the most likely etiology of the mass. Cardiac tamponade resulting in right-sided congestive heart failure was considered the likely source of the coelomic effusion, hepatomegaly, and peripheral edema. Postmortem examination confirmed serosanguinous pericardial effusion (hemopericardium), adhesion of the pericardial sac to the epicardium, and a focal dark red fluid-filled gelatinous area. Histopathology confirmed changes throughout the pericardium consistent with a diagnosis of mesothelioma. To the authors' knowledge, this case report documents the first antemortem treatment and postmortem definitive diagnosis of a pericardial mesothelioma in a leopard gecko.