Patients with non-functioning pituitary tumours: Are there differences between gender in post-operative hormone outcomes and does this relate to the pressure within the tumours?

The pituitary gland is an important gland that assists in control and release of hormones in the body. Abnormal growths in the gland, called “pituitary tumours or adenomas” can occur. The most frequent type requiring surgery is the non-functioning pituitary macroadenoma (NFPMA), which are tumours that don’t produce any excessive hormones but can be associated with hormone deficiences. At St Vincent’s Hospital, we have reviewed our own historical series of NFPMA. Between 1995 and 2010, 141 cases of NFPMA were operated on. It was observed that males were more likely than females to be to have 2 or more hormonal deficiencies at presentation. Post-operatively, 2 or more hormone deficiencies occurred more frequently in males and postmenopausal females but rarely in premenopausal females. So it appears that premenopausal females to have better hormonal outcomes. We have hypothesed that it may be related to lower pressure within tumours of premenopausal females. High pressure in the tumour is postulated to reduce blood flow to the pituitary gland and leads to death of normal hormone producing cells, thus less ability for hormonal recovery. This current project has been designed to confirm if gender differences in hormone deficiencies do occur after surgery. Also to demonstrate that pressure within tumours of premenopausal females in lower than males and postmenopausal females. These findings are important as they contribute to the understanding of hormonal differences in genders, which has not been fully examined before.