Case Study

Adrenal mass in an 8 year old FS German Shepherd mix

An 8-year-old FS German Shepherd mixed breed dog with history of polyuria and polydypsia was presented for urinary incontinence. The only pertinent finding on physical examination was a slightly tense abdomen on palpation. The only abnormality on urinalysis was isosthenuria. Abnormalities on CBC and blood chemistry were thrombocytopenia, eosinophilia, elevated ALT, ALP, and triglycerides. T4 and free T4 were both low. Low dose Dexamethasone test showed a pre-cortisol of 2.1 ug/dl, 4hr post-cortisol of 2.5, and an 8 hrs post-cortisol of 2.8.

DX

Right adrenal mass

Sonographic Differential Diagnosis

Right adrenal gland mass (adenoma, adenocarcinoma, pheochromocytoma). Unable to assess the potential for caval invasion due to the patients demeanor. Small left adrenal gland.

Image Interpretation

The left adrenal gland was small in this patient and measured 2.8 x 0.4 cm. The right adrenal gland comprised a 5.1 x 4.0 cm echogenic mass that was intimate with the vena cava. The patient was not cooperative in order to obtain vena cava imaging. The right kidney was deviated by the right adrenal gland mass. The kidneys themselves presented only minor degenerative changes and were otherwise normal.

Outcome

Blood pressure measurements and sedation with reassessment for caval invasion and potential adrenal resection or CT scan were recommended in this patient. Blood pressure measurements were within normal range. The patient was discharged with Trilostane. Results of an ACTH stimulation test 2 weeks later showed a pre-ACTH cortisol of 2.3 ug/dl and post-ACTH cortisol of 2.7.