Pheochromocytomas have been previously reported in horses, but successful antemortem diagnosis and surgical removal without recurrence of clinical signs has not been described. The aim of this study was to report the clinical presentation, diagnostic evaluation, surgical technique, anesthetic management, and post-operative care of a mare diagnosed with pheochromocytoma.
This clinical case report describes an 18-year-old Quarter Horse mare presented for recurrent episodes of colic, profuse sweating, muscle fasciculations and agitation over a 2-month period.
Clinical, clinicopathologic and ultrasonographic (transcutaneous, transrectal) abnormalities were consistent with a unilateral left-sided adrenal mass. Surgical removal of the mass was performed via a trans-costal approach with removal of the 18th rib and retraction of the left kidney to improve exposure. Associated vasculature was ligated, and the adrenal mass was removed and submitted for histopathology and immunohistochemistry.
A trans-costal surgical approach provided excellent visualization of the adrenal mass and allowed for identification and ligation of associated vessels. Total surgical and anesthesia time were 86 and 114 minutes, respectively. Several intra- (hypertension, tachycardia) and post-operative (colic with tachycardia, tachypnea, large colon pelvic flexure impaction and nasogastric reflux) complications were encountered and managed successfully.
Immunohistochemistry demonstrated positive labelling for synaptophysin and chromogranin A, confirming diagnosis of pheochromocytoma. The mare had recovered well at six-week recheck postoperatively and returned to training at six months postoperatively. No further clinical signs consistent with pheochromocytoma have been observed following removal.
Researchers concluded that the trans-costal approach allowed for surgical removal of a pheochromocytoma in a mare. Surgical removal of adrenal masses in horses may be associated with complications yet was successfully performed without subsequent recurrence of clinical signs associated with tumor presence and return to athletic use in this mare.
Thomas J O'Brien, et al. “Successful surgical removal of a pheochromocytoma in a mare via trans-costal approach.” Equine Vet J. 8 February 2023. doi: 10.1111/evj.13931.
List
Add
Please enter a comment