AVP and small cell lung carcinoma: Numerous causes have been associated with SIADH, including cerebral disorders (i.e., stroke, hemorrhage, infection, trauma, mental illness, and psychosis), increasing AVP pituitary release, tumors (more frequently, small cell lung cancer, but even extrapulmonary malignancies can cause ectopic AVP secretion), other pulmonary diseases, several drugs, surgical interventions, general anesthesia, infections such as human immunodeficiency virus (HIV) infection, stress, and many others [38, 40].