Fever of Unknown Origin: Could It Be a Pheochromocytoma? A Case Report and Review of the Literature.

Pheochromocytomas are rare tumors that arise from the adrenal medulla, with an incidence of less than 1 per 100,000 person-years. These tumors are characterized by excess catecholamine secretion and classically present with the triad of headaches, palpitations, and sweating episodes. However, the clinical presentation can be quite variable. Herein, we present a patient who presented with persistent fevers. An adrenal mass was incidentally discovered during the extensive investigation for the fever of unknown origin. Consequently, blood and urine tests were done and found to be consistent with a pheochromocytoma. The resection of this pheochromocytoma resulted in resolution of fevers. It is hypothesized that fevers in patients with pheochromocytomas occur due to the excess catecholamine or possibly due to interleukins. This clinical presentation serves as a learning point that adrenal incidentalomas in the setting of fever of unknown origin should not be ignored. It also reminds clinicians that pheochromocytomas which present with fevers may have tumor necrosis and many such patients are at risk for multisystem crises.