Tumours (usually but not invariably malignant), other ‘nonendocrine conditions’ and drugs can be associated with a wide variety of endocrine syndromes. ‘Ectopic’ hormone secretion, defined as the release of a hormone from a site different from the gland that normally produces it, has classically been recognized in the context of neoplasia, but it is now apparent that many hormones are synthesized by ‘nonendocrine’ tissue. Although a particular endocrinopathy may be associated with a specific type of tumour in a particular organ, the relationship is not invariable, and many neoplasms elaborate more than one hormonal substance at the same or at different times and thus produce a mixed endocrine picture....