Brief Answer: Major surgery Detailed Answer: I am assuming the size is indeed 13.5 cm and not a typo for 13.5 mm 13.5 cm for an adrenal tumor is quite large. Surgery must be considered promptly, after a comprehensive evaluation by an endocrinologist and endocrine surgeon. The following blood tests need to be done first: CBC CMP TSH Free T4 Plasma fractionated metanephrines Midnight salivary cortisol Aldosterone to Renin Ratio Further testing may be necessary based upon the results of the above tests to confirm or rule out the possibility of 'secretory' tumor ie to see if the tumor is producing any hormones in excessive amounts. One such tumor is called pheochromocytoma and if the tests for this come back positive then it is critical to be prepared medically for the surgery with specific medications, or otherwise it can be fatal during surgery. I dont think a 13.5 cm can be removed laparoscopically but I would defer to the surgeon's opinion on this. If only one adrenal is being removed then typically long term medication is not required. However in some situations a medication may be needed for few weeks and then gradually weaned off. It is a major surgery that requires general anesthesia and special expertise by adrenal surgeons. Several days' hospital stay is anticipated

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