Does GH replacement therapy in adult GH-deficient patients result in recurrence or increase in size of pituitary tumours?

OBJECTIVE: Hypopituitary GH-deficient patients have an increased cardiovascular mortality and GH replacement in this population has resulted in considerable therapeutic benefit. GH replacement involves administration of a potentially mitogenic substance to patients with a previous or residual pituitary tumour. Our objective was to evaluate whether GH replacement results in an increase in the size of pituitary tumours. METHODS: This was a non-randomised observational study on patients recruited from the endocrine clinic. All subjects had GH deficiency, proven on an insulin tolerance test and were divided into those who were or were not receiving long-term GH replacement. Comparison of change in pituitary size was made with interval radiological imaging of the pituitary. RESULTS: Seventy-five patients (40 men and 35 women) were in the study, 47 were on long-term GH replacement and there were 28 controls. The average length of treatment for the treated group was 3.6 patient years. Thirty-nine patients in the treated group had at least 2 years of GH treatment between imaging studies of the pituitary. Two patients in the treated group had an increase in pituitary size (non-functioning adenomas) and two in the control group (one functioning and one non-functioning adenoma adenoma). None of these four patients required further treatment. There was no statistically significant difference between the two groups. CONCLUSION: Using a representative cohort of hypopituitary patients attending an endocrine clinic, GH replacement was not associated with an increased pituitary tumour recurrence rate. Although the results are not conclusive, in the period of observation GH had little adverse effect but longer studies are required to be certain.

Bladder emptying in neonates.

Ultrasound scanning was used to determine whether bladder emptying is complete when a newborn baby micturates. Residual urine was detected in 6 females and 9 males while one female emptied her bladder completely. The residual volume was estimated in 11 subjects and ranged from 3.9 to 13.9 ml. Incomplete bladder emptying cannot be the main factor in explaining the sex incidence of urinary tract infection in neonates.

Acromegaly caused by pulmonary carcinoid tumours.

Two patients are described whose acromegaly was cured by removal of a bronchial carcinoid tumour. One had an enlarged pituitary fossa and evidence is presented that in this patient the tumour was not secreting growth hormone. The evidence available suggests that the tumour was producing a growth hormone releasing substance. It is suggested that some cases of the pluriglandular syndrome may be secondary to small bronchial carcinoid tumours that produce substances as yet unidentified, that stimulate the growth and hyperactivity of other endocrine tissue.