Primary hypoaldosteronism in a dog with pituitary and adrenal T-cell lymphoma.

A 7-year-old mixed breed dog was presented with a 2-week history of vomiting, diarrhoea, weakness and loss of appetite. Initial laboratory tests revealed hyponatraemia and hyperkalaemia consistent with hypoadrenocorticism. Basal plasma cortisol and adrenocorticotropic hormone concentrations were not suggestive of primary hypoadrenocorticism but the aldosterone concentration was undetectable. Abdominal ultrasound scan showed a mass within the left kidney and a nodular enlargement of the left adrenal gland. Cytological analysis revealed a large granular lymphoma. The dog died 17 days later. Post mortem histological and immunohistochemical examinations revealed a diffuse large granular T-cell lymphoma involving the mediastinal lymph node, kidneys, pancreas, adrenal and pituitary glands.