Dear X: It is always better to go in before the situation becomes critical, while the patient is the best surgical candidate. If the diagnosis has been made, and you are committed to eventually doing surgery, sooner is always better than later for a number of reasons. Medical treatment allows the neoplasms to grow larger and increases the chance of post-surgical complications. If the surgery only involves one adrenal, then Addison's is not an issue. (And Addison's is certainly not the end of the world. I have a bilateral adrenal at home who gets a monthly shot of Percorten and bounces around happily,her old normal self.) Post-surgical diabetes is a rare complication, whose incidence is markedly increased in animals with either long-standing insulinoma or prolonged medical treatment (another reason to do surgery early). The theory that these tumors "seed" is unproven, and an oversimplification. Yes, 40% of cases recur within 10 month, but this is not due to metastasis, but an unchecked (and as yet unidentified) metabolic condition which causes hyperfunction of islets of Langerhans. If your vet believes that these neoplasms tend to metastasize around the body, well that has been disproven in ferrets. Bottomline - an early surgery in the vast majority of cases, has the best chance of prolonging quality of life. With kindest regards, Bruce Williams, DVM [Sukie note: insulinoma is different from the possible pancreatic malignancy options for a different ferret which BAO discussed in another cross-post sent out tonight.] [Posted in FML issue 3608]