Adenocarcinoma of the Adrenal Gland in a Female Dog

Abstract

The aim of this article is to describe a case of adrenocortical neoplasm with manifestation of hyperadrenocorticism. Adrenocortical tumors originate from different types of cells and present varied clinical manifestations, which can be functional or non-functional. Adenocarcinomas are autonomous and functional in most cases, leading to excessive secretion of glucocorticoids, regardless of pituitary control. They corroborate the occurrence of hyperadrenocorticism (HAC) due to interference in the synthesis of cortisol. Clinical signs can be observed, as polyuria, compensatory polydipsia, polyphagia, blood pressure alterations, cardiac, renal and endocrine dysfunctions, among others. Diagnosis can be made in various ways, such as urinary cortisol measurements, adrenocorticotropic hormone stimulation, low-dose dexamethasone suppression tests, and imaging tests and histopathology. This article reports the case of a 13-year-old mixed-breed female dog with signs of polyuria and polydpsia. After discarding the initial diagnoses (diabetes mellitus and/or renal alterations), HAC was suspected, with further tests being performed. The test results showed an increase in the adrenal region, and adrenalectomy and hormone replacement with trilostane were recommended. The diagnosis of HAC was confirmed by histopathology as HAC secondary to adrenal gland adenocarcinoma. The patient also developed diabetes mellitus during postoperative treatment with prednisone, which made it necessary to discontinue the medication.