Would you aspirate an adrenal mass in a dog?

In a recent study of 50 dogs with 58 adrenal gland masses (including 23 dogs with pheochromocytoma) undergoing fine-needle aspiration, complications were reported in four (8%) dogs. Three haemorrhages (mild or moderate) and one death occurred 28 hours later in a dog with pheochromocytoma due to acute respiratory distress syndrome (possibly related to laryngeal paralysis). No hypertensive crisis was reported. There was also no relationship between the method of fine-needle aspirate or type of needle used and occurrence of complications. Moreover, based on the recollection of 65 radiologists, who performed approximately 200 fine-needle aspirates of adrenal gland lesions or masses, a death rate of approximately 1% was estimated. (Pey et al. 2020)

In another study of 19 dogs with adrenal gland lesions (including nine dogs with pheochromocytoma), fine-needle aspiration lead to complication in one (5%) dog. The dog had a pheochromocytoma and developed ventricular tachycardia following aspiration. However, the complication may have been unrelated to the procedure because the dog presented with tachycardia and pericardial effusion. (Sumner et al. 2018)

Adrenal cytology has been shown to be able to discriminate the origin (cortical or medullary) of an adrenal neoplasm with high diagnostic accuracy (90-100%), but not necessarily benign from malignant lesions. (Bertazzolo et al. 2014)

In summary, despite the negative perception by veterinarians, percutaneous US-guided fine-needle aspiration of adrenal gland lesions in dogs is considered a minimally risky procedure with complications reported in around 5-8%, and a death rate of around 1%.  

To answer this question. Yes, I would consider aspirating an adrenal gland mass in the diagnostic investigation of adrenal gland lesions, but only under certain circumstances where it would change the owner's decision to treat. For example, if there is an incidental adrenal gland mass where I am not sure whether I should consider further diagnostics, surgery or monitoring; or if I would like to try to determine if the adrenal gland mass is primary or metastatic neoplasia. Although the risks of complications are low, there is still a 1% risk of death from the procedure!

Vets, if you have a question about this topic or a dog with an adrenal gland mass or lesion that you are not sure whether you should aspirate, please do not hesitate to get in touch by clicking here.

If you would like a copy of any of the listed publications, please click on the ‘author’ links provided in this blog.