Possible Causes of Diabetes Insipidus in a Patient with a Malignancy

 

The most common cause of DI is a tumor (primary or metastatic) to the region of the pituitary or hypothalamus.

 

Additional reasons for DI include:

(1) renal failure due to obstructive uropathy

(2) renal disease associated with amyloidosis

(3) other causes of renal failure

(4) drug-induced nephrogenic diabetes insipidus (cyclophosphamide, other)

(5) drug-induced reduction in the secretion of antidiuretic hormone (ADH)

 

Wassermann hypothesized the possibility of a small cell undifferentiated carcinoma of the lung metastasizing to the pituitary and also secreting an ADH-like peptide with decreased functional activity. This would result in a normal antigenic assay for ADH yet diabetes insipidus.