Case Study

Right Adrenal Mass invading the Vena Cava and obstructing the Hepatic Vein inflow in a 12 year old MN Chihuahua Mix

A 12-year-old MN Chihuhua Mix dog was presented for weight gain in the last 4 weeks and severe peretonial effusion.

Sonographic Differential Diagnosis

pheochromocytoma, adenocarcinoma

Image Interpretation

The right adrenal gland comprised a mass measuring 4.92 x 2.54 cm at the cranial pole and 1.63 cm at the caudal pole. The right adrenal gland was particularly vascular- invading the vena cava and obstructing the hepatic vein inflow. The left adrenal gland was enlarged and irregular measuring 2.34 x 1.52 cm at the cranial pole and 0.6 cm at the caudal pole.

The liver was enlarged with isoechoic nodular changes and hepatic vein dilation.

A large amount of mildly echogenic ascites was noted throughout the abdomen. Enhanced hyperechoic omentum was noted throughout the midabdomen.

Rapid view of the heart revealed no evident pathology, in fact it appeared volume contracted, likely owing to poor venous flow through the caval system to the right atrium.

DX

Right adrenal mass, likely pheochromocytoma invading the vena cava and obstructing the hepatic vein inflow secondary to passive congestion and ascites.

Outcome

Palliative therapy with abdominocentesis would be indicated as well as treatment for any systemic
hypertension. Urine catecholamine test is recommended. If it is positive then pheochromocytoma is
likely the diagnosis; however, differentials include adenocarcinoma. Prognosis is poor.