Case Study

Right adrenal mass and irregular left adrenal in a 10 year old FS Shih Tzu dog

A 10-year-old FS Shih Tzu dog was presented for a high dose dexamethasone suppression test (HDDS). The dog had a history of polyuria, polydypsia, coughing, recent normal blood work, and a diagnosis of hyperadrenocorticism on low dose dexamethasone suppression test (pre-dexamethasone 7.3 ug/dL, second sample 4.5 ug/dL, and third sample 4.2 ug/dL). HDDS results were pre-dexamethasone 5.8 ug/dL, second sample 4.9 ug/dL, and third sample 3.8 ug/dL.

A 10-year-old FS Shih Tzu dog was presented for a high dose dexamethasone suppression test (HDDS). The dog had a history of polyuria, polydypsia, coughing, recent normal blood work, and a diagnosis of hyperadrenocorticism on low dose dexamethasone suppression test (pre-dexamethasone 7.3 ug/dL, second sample 4.5 ug/dL, and third sample 4.2 ug/dL). HDDS results were pre-dexamethasone 5.8 ug/dL, second sample 4.9 ug/dL, and third sample 3.8 ug/dL.

Sonographic Differential Diagnosis

The adrenal glands are consistent with adenomas or adenocarcinoma, with dystrophic mineralization, or myelipomas.

Image Interpretation

The left adrenal gland was prominent and irregular, with mixed echogenic parenchyma and focal mineralization measuring 1.4 x 2 cm. No vascular invasion was noted. A mass of mixed hyperechoic changes was evident on the right adrenal gland, however there was no evidence of vascular invasion. This mass measured 2.8 x 2.6 cm.

DX

Right adrenal mass and enlarged irregular left adrenal with mineralization

Outcome

Surgical resection of the right adrenal gland was highly recommended, as well as biopsy of the left adrenal gland. Blood pressure measurements were recommended with empirical treatment for potential thromboembolic disease due to the nature of the cough. Surgical consultation was strongly recommended, but owners declined the referral. The patient was treated with Aspirin therapy, Tussigon, Clavamox, and started on Lysodren. A few weeks later the owner reported the patient’s cough had resolved. A recheck ACTH stimulation showed stable values on Lysodren. At last recheck ACTH stimulation several months later found improved, but still too elevated, and the Lysodren dosage was increased.

Clinical Differential Diagnosis

Polyuria/polydypsia – adrenal disease (Cushing’s, neoplasia). Cough – infection (viral, bacterial, fungal), pulmonary edema, tracheal/pulmonary hypersensitivity, trauma, mediastinal/intra-thoracic fat accumulation.