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

Abstract

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.

From transitory erythema to pheocromocytoma

“…Actually, IL-6 is either produced by the tumour itself (and immunohystochemistry on the adrenal tumour should confirm it) or it is stimulated by circulating norepinephrine as a reactive response (18,19). Overall, pheocromocytoma, a rare tumour with an incidence of 1/100 000 person-year, associates the classical triad of headache, palpitations and sweating but large variations of clinical presentation is described including transitory erythema as seen in this case without fever (20). This atypical manifestations complicate the index of suspicion in a very severe condition if left untreated.…”

Inflammation-based scores in patients with pheochromocytoma

“…tumors showed that leucocytosis and neutrophilia were a relatively common finding (15). Furthermore, other studies have found that not only CBC parameters but also acute-phase proteins, such as elevated Creactive protein, were higher in patients with pheochromocytoma than healthy subjects or patients with other types of hypertensive conditions (9,14,28,29).…”

Identification of vital prognostic genes related to tumor microenvironment in pheochromocytoma and paraganglioma based on weighted gene co-expression network analysis

“…According to the previous studies, it was generally acknowledged that systemic inflammation played a central role in tumorigenesis and cancer progression. Several reports have shown that fever of unknown origin and systemic inflammatory syndrome were associated with IL-6 producing pheochromocytoma, which tended to have a larger tumor volume as well as an elevated risk of pheochromocytoma multisystem crisis [ 11 , 12 ]. Furthermore, the inflammation has long been considered to be closely associated with the pathogenesis of RCC [ 13 ].…”