Study challenges size-based assumptions for canine adrenal masses
Bottom line
Version 1
Dogs with incidentally discovered adrenal masses may need a more nuanced preoperative workup than lesion size alone would suggest. In a retrospective JAVMA study of 214 dogs that underwent laparoscopic adrenalectomy, investigators found that for canine incidental adrenal masses, lesion size did not predict whether the mass was malignant. The study also reported excellent outcomes after laparoscopic adrenalectomy, adding to evidence that minimally invasive adrenal surgery can be effective in carefully selected dogs. The authors were Audrey K. Cook, Philipp D. Mayhew, and Federico Massari. (pubmed.ncbi.nlm.nih.gov)
Why it matters: For veterinary professionals, the findings challenge a common assumption that larger incidental adrenal lesions are more likely to be malignant. That matters because size thresholds often shape referral, surgical planning, and conversations with pet parents. The broader adrenal incidentaloma literature, including imaging and endocrine guidance in human medicine, has long shown that size is an imperfect proxy for biologic behavior, and the canine data appear to reinforce that point. In practice, that could push clinicians toward a more comprehensive assessment of imaging characteristics, hormonal activity, vascular invasion, comorbidities, and surgeon experience when deciding whether to monitor or refer for adrenalectomy. (pubmed.ncbi.nlm.nih.gov)
What to watch: Expect follow-up discussion around which preoperative factors, beyond size, best identify malignant canine adrenal incidentalomas and help guide case selection for laparoscopy. (pubmed.ncbi.nlm.nih.gov)
Version 2
A new JAVMA study suggests veterinary teams should be careful about relying on lesion size when evaluating canine incidental adrenal masses. Reviewing 214 dogs that underwent laparoscopic adrenalectomy, the authors found that the malignant potential of an incidental adrenal mass could not be predicted by size alone, while postoperative outcomes after laparoscopic adrenalectomy were excellent. The paper addresses a familiar clinical dilemma as advanced imaging turns up more unexpected adrenal findings in dogs. (pubmed.ncbi.nlm.nih.gov)
That question isn’t new. Earlier JAVMA work from Audrey K. Cook and colleagues described incidental adrenal gland lesions on ultrasound in dogs and highlighted how commonly these findings emerge during workups for unrelated problems. In parallel, both veterinary and human adrenal literature have wrestled with the same issue: whether an incidental mass is hormonally active, technically resectable, or malignant, and whether size can safely guide management. Across that literature, size has often been used as a shorthand risk marker, but it has never been a perfect one. (pubmed.ncbi.nlm.nih.gov)
The new study specifically compared dogs with incidental adrenal masses against dogs with clinical adrenal masses and looked for preoperative indicators of histologic diagnosis in the incidental-mass group. While the full article details weren’t fully available in the search results, the abstract summary indicates the central takeaway was clear: lesion size did not distinguish benign from malignant incidental lesions. That’s notable because laparoscopic adrenalectomy has historically been approached more cautiously as adrenal masses get larger or look more suspicious, especially when malignancy or local invasion is a concern. (research-portal.uu.nl)
The surgical piece of the paper is just as relevant. Prior veterinary data comparing laparoscopic and open adrenalectomy in dogs have found laparoscopy can offer favorable perioperative outcomes in selected cases, including some dogs with incidentalomas, while open surgery remains important for more invasive or higher-risk tumors. Broader adrenal surgery literature also supports minimally invasive adrenalectomy for appropriately chosen masses, though suspected invasive malignancy still shifts many surgeons toward an open approach. The JAVMA paper appears to strengthen the case that, in dogs selected for laparoscopy, outcomes can be very good. (pubmed.ncbi.nlm.nih.gov)
I didn’t find a press release or direct expert quote tied specifically to this new paper, but the surrounding literature points to the same practical tension clinicians face every day: incidentalomas are increasingly common, yet preoperative certainty is limited. Reviews of incidental adrenal lesions emphasize that imaging can characterize many lesions, but indeterminate masses remain a mixed group that includes both benign and malignant pathology. That helps explain why a single variable like diameter may not perform well enough for surgical decision-making on its own. (pubmed.ncbi.nlm.nih.gov)
Why it matters: For general practitioners, internists, radiologists, and surgeons, this study supports a shift away from simple size-based assumptions when counseling pet parents after an incidental adrenal finding. A small lesion shouldn’t automatically be treated as low risk, and a larger lesion shouldn’t automatically be framed as malignant based on diameter alone. Instead, the work underscores the value of integrated staging and referral decisions that consider imaging phenotype, evidence of vascular invasion, endocrine testing, patient stability, and local surgical expertise. It may also help practices have more balanced discussions with pet parents about the role of laparoscopy, especially when a mass appears resectable and the dog is otherwise a good candidate. (pubmed.ncbi.nlm.nih.gov)
What to watch: The next step is likely more refinement around risk stratification, specifically which combination of CT features, biochemical findings, and clinical presentation best predicts malignancy before surgery. It will also be worth watching whether future veterinary studies define clearer selection criteria for laparoscopic versus open adrenalectomy, particularly for larger masses or lesions with equivocal imaging findings. (pubmed.ncbi.nlm.nih.gov)