Pituitary macroadenoma in a cat with diabetes mellitus, hypercortisolism and neurological signs

A 13-year-old neutered male European shorthair cat was presented because of blindness and behavioural abnormalities. On physical examination, abnormal behaviour, compulsive walking, circling, continuous vocalisation, and blindness were the main neurological signs. In addition, abdominal alopecia, thin and inelastic skin, weight loss despite polyphagia, polyuria and polydipsia were present. Laboratory investigation revealed diabetes mellitus and pituitary-dependent hypercortisolism. Diagnostic imaging showed bilaterally enlarged adrenals and a large pituitary mass. Histopathological and immunohistochemical examination confirmed the clinical diagnosis of an ACTH-producing pituitary macroadenoma.