Case Study

Myelolipoma diagnosed by ultrasound-guided FNA in a 10 year old FS Labrador Retriever

10 year old FS Labrador Retriever dog was presented for a recheck urinalysis due to a persistent urinary tract infection. The CBC showed thrombocytosis. The blood chemistry found hyperbilirubinemia, hyperphosphatemia, hypernatremia, hyperamylasemia, and hypertriglyceridemia. The results of the ACTH stimulation test were within normal limits. The urinalysis showed a normal specific gravity, proteinuria, elevated WBC without the presence of bacteria. The urine microalbumin and urine protein/creatinine ratio were elevated.

DX

Myelolipoma with possible mixed lymphoid tissue.

Sonographic Differential Diagnosis

Right adrenal mass, non invasive: Pheochromocytoma, adenoma, adenocarcinoma, myelolipoma, hyperplasia.

Image Interpretation

A mixed hyperechoic right adrenal mass is noted. No evidence of vascular invasion is present in any of the views. Left adrenal is sonographically normal.

Outcome

Cytology results were most compatible with a myelolipoma with possible mixed lymphoid tissue. The patient was discharged with a course of antibiotics and medication to treat her hypertension.

Clinical Differential Diagnosis

Hyperadrenocorticism (Pituitary or adrenal gland dependent with a secondary protein losing nephropathy, or atypical, i.e. overproduction of sex hormones), pheochromocytoma, primary protein-losing nephropathy with secondary hypertension, glomerulonephritis (immune-mediated, infectious (Dirofilaria immitis, Borrelia burgdorferi, Bartonella spp., Leptospira spp.) amyloidosis.