Among the most interesting manifestations of
neoplasms is the production of functional
peptides and
hormones that may induce unique clinical syndromes. It has become obvious in the last decades that a wide range of endocrine
tumors secrete
hormones not normally associated with the tissue in which the
neoplasm arises. The resultant syndromes, some of which resemble other endocrine entities, can be the first clinical manifestation of malignant disease or a harbinger of
cancer recurrence. The development of these disorders does not necessarily correlate with
cancer stage or unfavorable prognosis. Early recognition of
paraneoplastic endocrine syndromes is clinically important as it might lead to the detection of underlying
malignancy and might prevent delay in treatment. Because
paraneoplastic endocrine syndromes often cause considerable morbidity and mortality, effective treatment can improve patient quality and length of life. The aim of this study was to review the most common and the most specific
paraneoplastic syndromes associated with the presence of
ectopic hormone production. We emphasize the importance of considering the
ectopic hormone production in the differential diagnosis of various endocrine entities.