A primary cardiac neuroendocrine carcinoma of the right ventricle in a dog: a case report

Cardiac neuroendocrine carcinoma, also known as chemodectoma, is one of the most common heart tumors in dogs that is usually located at the heart base. In this case report, echocardiography and computed tomography (CT) were performed to diagnose an atypical location of primary cardiac neuroendocrine carcinoma in a nine-year-old dog. The patient had a history of resection, recurrence, and re-operation for a right thyroid tumor. An echocardiographic examination identified an oval-shaped, mobile mass prolapsing through the tricuspid valve, which extended from the heterogeneous mass in the dilated coronary sinus to the right atrium. In addition, a portion of the right ventricular wall was observed as a thickened heterogeneous mass. CT also revealed a heterogeneous contrast-enhancing mass filling the dilated coronary sinus and projecting into the right atrium, forming an oval shape that was associated with a thickened, heterogeneous right ventricular wall. Considering the location of the mass and the patient’s history, thyroid carcinoma metastasis or primary hemangiosarcoma was suspected. A surgical biopsy of the right ventricular wall mass was performed, and the histopathological and immunohistochemical findings confirmed the mass to be a primary neuroendocrine carcinoma.