[Paraneoplastic endocrine syndromes].

In some instances, tumors can produce signs and symptoms at a distance from the tumor or its metastases. These are defined as paraneoplastic syndrome or humoral syndrome associated with neoplasms. Paraneoplastic syndromes can arise from circulating substances secreted by tumors. The most well-recognized and frequent concomitant of neoplasms is the production of hormones by nonendocrine tumors. These are usually called ectopic hormone-producing tumors and bring about clinically endocrinologic manifestations secondary to hormone excess in patients with nonendocrine tumors. Paraneoplastic endocrine syndromes frequently observed are Cushing's syndrome due to ectopic production of ACTH, SIADH due to ectopic production of ADH, hyper-calcemia, hypoglycemia and so on. In order to establish a paraneoplastic etiology for alteration in hormone production, evidence that the hormone is produced by the tumor must be proved. Paraneoplastic endocrine syndromes should be distinguished from hormone production by benign cells, hormone production by a malignancy of an endocrine organ or alterations in hormone production being due to infiltration into the endocrine organ by a primary tumor. The treatment of ectopic endocrine syndromes should be directed primarily at the tumor. Because the course of this type of syndrome usually runs parallel to the course of the underlying tumor, the ectopically produced hormone can be a useful monitoring marker of the disease.