The parathyroids are the glands most often affected by FMEN1 and the pituitary becomes overactive in about 1 in 6 persons. The cause of pitutary overactivity is usually a benign tumour called a prolactinoma . Kallmann's Syndrome Kallmann's syndrome is a form of hypogonadotrophic hypogonadism characterised by an absence of GnRH , a hormone naturally released by the hypothalamus. A support group exists specifically for sufferers of hypogonadotrophic hypogonadism. If the blood supply to the pituitary is restricted, the gland tissue can die resulting in hypopituitarism.
Infarctions can occur as a result of impaired blood flow to the pituitary gland or head trauma.
Rathke's cleft cysts are not tumours, but instead are classified as developmental abnormalities. Like craniopharyngiomas , these cysts form during early development of the foetus from a structure known as Rathke's pouch. Small Rathke's cleft cysts are not uncommon and do not usually cause any symptoms. Problems can occur if these cysts enlarge and interfere with pituitary production or exert pressure on the optic chiasm. Occasionally one or both eyes may be abnormal or the nerves connecting the eyes to the brain may be abnormal.