Hyperprogesteronism Due to Bilateral Adrenal Cortex Carcinomas in a Cat with Diabetes Mellitus

An 8-year-old male castrated Russian Blue cat presented with symptoms such as polyuria, polydipsia, polyphagia, abdominal enlargement, unkempt and easily epilated hair coat, and abdominal alopecia. Initially diagnosed with diabetes mellitus, further investigation revealed severe bilateral enlargement of the adrenal glands. Despite suspicions of hypercortisolism, cortisol levels were undetectable, while high progesterone concentrations were found. Histological examination identified the adrenal masses as bilateral adrenal carcinomas of the adrenal cortex. This case demonstrated that adrenal gland tumors could secrete sex hormones like progesterone instead of cortisol, with clinical signs of hyperprogesteronism mimicking those of hypercortisolism.