Interleukin-6 producing pheochromocytoma/paraganglioma: case series from a tertiary referral centre for pheochromocytomas and paragangliomas.

Introduction In addition to catecholamines, pheochromocytomas and paragangliomas (PPGL) may secrete interleukin-6 (IL-6). IL-6 contributes to the development of unusual symptoms, which may hinder the diagnosis. Patients and methods We report the clinical course and subsequent treatment of IL-6 producing PPGL in three patients from a single tertiary referral centre for PPGL patients in the Netherlands. Conclusion PPGL combined with persistent elevated inflammatory markers, either in the presence or absence of pyrexia, raised suspicion of IL-6 overproduction in these three patients. Although surgical resection of the tumour is the only curative treatment option, our case series adds to the accumulating evidence that alpha-blockers might be effective in these patients.