The ectopic ADH syndrome (Fig. 21.11) is caused by the production of ADH by neoplasms with endocrine characteristics. This syndrome is also referred to as the Schwarz-Bartter syndrome or the syndrome of inappropriate ADH secretion (SIADH). Although ectopic ADH syndrome is observed in patients with various types of neoplasms, almost all cases of the disorder develop in patients with small-cell lung carcinoma.
