Familial Catecholamine-Secreting Tumors - Three Distinct Families with Hereditary Pheochromocytoma

Phaeochromocytomas (PHEOs) and paragangliomas (PGLs) are catecholamine-secreting tumors, that arise from chromaffin cells of the adrenal medulla and extra-adrenal sites. Extra-adrenal phaeochromocytomas are called paragangliomas (Landers et al., 2005). The Prevalence of these tumors is 1:4500 and 1:1700 and an annual incidence of 3-8 cases per 1 million per year in the general population. PHEOs/PGLs arise from three anatomically parts of the neural crest derived sympathy-adrenal system: adrenal medulla, sympathetic, and parasympathetic paraganglia (Kantorovich et al., 2010). Extra-adrenal parasympathetic paragangliomas which are located predominantly in the head and neck are approximately 95% nonsecretory. Pheochromocytomas typically occur in about 85% of cases from adrenal medullary chromaffin tissue and in about 15% of cases from extra-adrenal chromaffin tissues (Elder et al., 2005).