Endocrine aspects of pituitary stalk enlargement.

Four patients with various endocrine deficiencies of a predominantly hypothalamic nature are described, in whom computed topographic scans demonstrated pituitary stalk enlargement. In one, a disseminated papular skin eruption with regional pleomorphism and spontaneous regression appeared 4 years after the development of the initial symptoms of diabetes insipidus, and led to a diagnosis of xanthoma disseminatum, a rare type of histiocytosis. It is suggested that this patient's endocrine dysfunction is also due to histiocytic involvement of the hypothalamus and/or pituitary stalk. In view of the prolonged lapse of time between the initial endocrine manifestations and the eventual diagnosis, even though no cause is apparent in the other three patients, it is suggested that close follow-up be carried out to rule out such a possibility in patients with this endocrine-radiological entity.