Hyperadrenocorticism and hyperprogesteronemia in a cat with an adrenocortical adenocarcinoma

A seven-year-old, neutered male domestic shorthair cat was evaluated for po orly regulated diabetes mellitus and increased skin fragility. Imaging stud ies revealed a right adrenal gland tumor, but cortisol testing did not supp ort a diagnosis of hyperadrenocorticism. Serum concentrations of progestero ne and testosterone were increased compared with a group of normal cats, an d the clinical signs were attributed to hyperprogesteronemia. At necropsy, a diagnosis of adrenocortical adenocarcinoma was confirmed, and immunohisto chemical staining confirmed the presence of progesterone within the tumor. Clinical signs of hyperadrenocorticism in cats may occur due to increased s erum concentrations of hormones other than cortisol.