[Ectopic hormone production].

Ectopic hormone production by tumors is one particular form of paraneoplasia. Syndromes caused by inappropriate ectopic secretion of hormones or biologically active molecules with hormone-like effects may help to detect the presence of a tumor or its localization, and in monitoring the efficiency of therapy. Ectopic hormone production is difficult to demonstrate unequivocally. The pathogenesis remains unknown but may be elucidated in the near future by research into the pathogenesis of tumors at the molecular level. The tumors most frequently associated with ectopic hormone production are bronchogenic and pancreatic carcinomas, carcinoids, and thymomas.