Serendipity in the diagnosis of pheochromocytoma.

Objectives: Pheochromocytomas are increasingly being discovered incidentally on imaging studies performed without clinical suspicion of the existence of an adrenal lesion. We aimed to determine the rate of diagnosis of adrenal pheochromocytoma as an incidental finding during a recent 7-year period.

Methods: We obtained the Department of Pathology database to study all the patients at our institution with newly diagnosed pheochromocytomas in the 7-year period from 2005 to 2011 to determine the clinical presentation and the means of diagnosis.

Results: In 40 (70.2%) of the 57 patients, an adrenal pheochromocytoma was detected in an imaging study performed without suspicion of an adrenal lesion. There were 13 chest computed tomography studies-8 to evaluate for possible pulmonary emboli. Other indications included abdominal pain or discomfort (n = 8), trauma (n = 3), abnormal liver function tests (n = 3), suspect renal artery stenosis (n = 3), hematuria (n = 2), colitis (n = 2), and 4 miscellaneous indications.

Discussion: Our study documents that the commonest current means of initial detection of pheochromocytoma is by serendipitous discovery. In 16 of our 40 patients with serendipitously discovered pheochromocytomas, there were no clinical symptoms of pheochromocytoma; these were true incidentalomas. More than two thirds of the new cases of pheochromocytoma were detected by serendipity (found during studies not performed to evaluate for pheochromocytoma), approximately one third were true incidentalomas (pheochromocytomas in patients without symptoms).

Conclusions: In a 7-year period at a single institution, 40 patients, 70% of new cases of surgically proven pheochromocytoma, were initially detected by serendipity. Sixteen patients, 40% of those incidentally discovered represented true examples of "incidentalomas."