INTERLEUKIN-6 SECRETING PHEOCHROMOCYTOMA ASSOCIATED WITH CLINICAL MARKERS OF INFLAMMATION

Phaeochromocytomas have been shown to produce not only catecholamines but other neuropeptides and hormones, with a variety of clinical manif estations. We report a 70-year-old female patient with phaeochromocyto ma exhibiting sustained hypertension, low-grade fever, thrombocytosis, and elevated levels of plasma fibrinogen and C-reactive protein. Seru m interleukin (IL)-6 levels were significantly elevated, whereas serum lL-1 alpha and IL-1 beta were not detectable. After surgical removal of the tumour, hypertension and low-grade fever disappeared, and the l aboratory findings including serum IL-6 concentrations became normal. Immunohistochemical study of the tumour showed positive staining for I L-6. Culture of the resected tumour revealed the production of large a mounts of IL-6. It is suggested that IL-6 secreted by the tumour was r esponsible for some of the clinical manifestations in this patient.