The development of trophic hormone deficiency with anterior pituitary tumours.
As the disease progresses, there is a characteristic order in the development of hormone deficiency. Usually, GH secretion fails first, with ACTH secretion failing much later on. Prolactin deficiency is rare, except when associated with an early failure of lactation in Sheehan's syndrome. ADH deficiency is virtually unknown in patients with anterior pituitary tumours, but may be seen with other causes of hypopituitarism (e.g. head trauma).
