Case Study

Adrenocortical adenoma diagnosed on surgical excisional biopsy in a 12 year old MI Shih Tzu

A 12-year-old M intact Shih Tzu dog was presented for polydipsia of several months’ duration. The serum biochemical profile revealed an elevated urea, increased ALT, increased GGT enzyme activities, hyperphosphatemia, hyperkalemia, hypercholesterolemia, and elevated triglycerides. Thrombocytosis was present on the CBC.

Sonographic Differential Diagnosis

Left adrenal mass, non invasive – adenoma, adenocarcinoma, pheochromocytoma, and less likely benign hyperplasia.

Image Interpretation

The right adrenal gland is enlarged with irregular contour, mass appearance, and focal hyperechoic nodule at the caudal pole. Loss of structural detail is evident. An intimate relationship with the vena cava is present without obvious invasion. The left adrenal is uniform with normal size and contour indicating a unilateral pathological process.

DX

Adrenocortical adenoma

Outcome

The patient was referred to a board certified surgeon for an exploratory surgery. A cholecystectomy was performed due to concurrent gall bladder mucocele (diagnosed sonographically). Culture and sensitivity of the bile was negative for bacterial growth. A biopsy of the gallbladder showed marked cystic, mucinous, gallbladder hyperplasia. The liver sample revealed mild, chronic, lymphocytic hepatitis with a hydropic vacuolar hepatopathy. A 3 cm long adrenal mass was visualized, and a right adrenalectomy was performed. The dog did well post-operatively and is doing well clinically according to the owner.

Clinical Differential Diagnosis

Hyperadrenocorticism – pituitary dependent or adrenal dependent tumor (adenoma or adenocarcinoma), adrenal tumor causing the overproduction of sex hormones (atypical Cushing’s disease). Hyperlipidemia, chronic active hepatitis, cholestasis, vacuolar hepatopathy.