Pituitary Deficiency in Patients With Pituitary Tumours

SUMMARY In 44 cases of tumours of the pituitary gland, the incidence of pituitary deficiency was determined; eight patients were severely hypopituitary, 16 had partial pituitary deficiency, and in 20 there was no evidence of loss of endocrine function. There was an increased incidence of hypopituitarism in patients with purely chromophobe tumours and in those with an upward extension above the diaphragma sellæ of more than 1·5 cm. There was no relation between the incidence of hypopituitarism and the size of the pituitary fossa on X‐ray examination. In the 28 patients explored by transfrontal craniotomy, there was a close association between the development of both severe hypopituitarism and diabetes insipidus and damage to the median eminence of the hypothalamus or the infundibulum. Despite some difficulty in the accurate classification of pituitary function, this investigation has demonstrated the importance of the integrity of the hypothalamic‐hypophyseal neuro‐vascular connections in the maintenance of pituitary function, even in the presence of a pituitary tumour. It is hoped that this will be of value in the management of patients undergoing operations for pituitary tumours, and in rare cases may influence the type of surgical procedure employed.