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CASE REPORT article

Front. Vet. Sci.

Sec. Veterinary Clinical, Anatomical, and Comparative Pathology

Volume 12 - 2025 | doi: 10.3389/fvets.2025.1632432

Case Report: Trilostane therapy in a dog with recurrent adrenocortical carcinoma producing an array of steroid hormones

Provisionally accepted
  • 1University Veterinary Teaching Hospital Sydney, Camperdown, Australia
  • 2Diagnostic Endocrinology Service, Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, United States
  • 3Veterinary Pathology Diagnostic Services, Sydney School of Veterinary Science, University of Sydney, Sydney, Australia

The final, formatted version of the article will be published soon.

A 10-year-old neutered male poodle-cross was presented with signs of progressive hyporexia and marked polyuria and polydipsia (PU/PD) of two months' duration. Right unilateral adrenalectomy was performed 24 months prior, and adrenocortical carcinoma with no evidence of metastatic disease was diagnosed. Tumour aldosterone secretion was suspected due to persistent hypokalaemia and systemic hypertension. Upon re-presentation, the dog had a pot-bellied appearance, dermatological changes (symmetrical alopecia along the trunk, elbows, and hocks, with decubital ulcers), systemic hypertension, and marked hypokalaemia unresponsive to oral potassium supplementation, raising concerns for an endocrine disorder. Abdominal CT confirmed mass lesions in multiple liver lobes near the previous adrenalectomy site, and cytology confirmed adrenocortical carcinoma metastases. Regional and cranial mediastinal lymphadenomegaly, as well as prostatomegaly, were observed, while no abnormalities were detected in the left adrenal gland. A serum adrenal profile identified marked elevations in progesterone, androstenedione, estradiol, and testosterone concentrations pre-and post-ACTH. Serum aldosterone and cortisol concentrations pre-and post-ACTH were within reference intervals, noting the dog had been treated with spironolactone for eight weeks at measurement. Trilostane therapy was initiated with an initial positive response, including reduced PU/PD and resolution of pot-bellied appearance. A significant reduction of steroid hormones was documented later. Signs returned about four months into trilostane treatment with evidence of progressive disease on repeat CT and adrenal profile. The dog is managed with palliative trilostane, 14 months since liver metastasis diagnosis.This case highlights an initial clinical response to trilostane in a dog with metastatic, functional adrenocortical carcinoma (ACC), demonstrating short-term control of clinical signs. The variation in presentation between initial diagnosis and relapse prompted a hypothesis of a shift in tumour steroidogenic activity-a phenomenon rarely documented in veterinary literature. It underscores the diverse manifestations arising from excess production of multiple steroid hormones, including precursors. It also supports adrenal profiling in complex cases and confirms trilostane's utility as a palliative therapy in non-resectable or metastatic ACC.

Keywords: case report, Adrenocortical Carcinoma, Hyperaldosteronism, Hyperandrogenism, Trilostane

Received: 21 May 2025; Accepted: 19 Aug 2025.

Copyright: © 2025 Cheung, Giori, Griebsch, Courtman, Podadera and Thompson. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Chloe Cheung, University Veterinary Teaching Hospital Sydney, Camperdown, Australia

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