Oat cell carcinoma of bronchus presenting as an acute psychiatric illness in young women.

Two young women are described who presented with an acute psychiatric illness, due to the metabolic effects of inappropriate anti-diuretic hormone (ADH) secretion. In both patients symptoms were promptly abolished by correction of the biochemical disturbance and subsequent investigations revealed hitherto occult oat cell carcinoma of bronchus. These patients demonstrate the value of routine laboratory investigations in all patients with an acute psychiatric illness and illustrate that bronchial carcinoma must be considered in patients of all age groups presenting with the syndrome of inappropriate ADH secretion.