Endocrine Abstracts

Introduction: Growth hormone (GH) replacement is widely used in the management of patients with adult-onset (AO) GH deficiency (GHD). In most cases, AO-GHD arises as a result of pituitary/peri-pituitary tumours and/or their treatment. The aim of this study was to examine the effect of GH replacement on growth/recurrence of non-anterior pituitary parasellar tumours.

Methods: Fifty consecutive patients (21 males; mean age 45.9) with severe AO-GHD (peak serum GH 9 milli-unit per litre or less on dynamic testing) consequent upon a peripituitary tumour were studied. The primary diagnoses were: craniopharyngioma (28), germ cell tumour (8), arachnoid cyst (4), meningioma (4), glioma (4), mensenchymal tumour (2). 37 patients (74%) had received pituitary radiotherapy. All patients were treated with a dose titration regimen to maintain serum IGF-1 between the median and upper end of the age-related reference range. Surveillance imaging (MRI 70%, CT 16%, 14% both) was performed at baseline (prior to GH), at 6-12 months and then again yearly or as clinically indicated. Median follow up was 36 months (range 7-129). All images were reviewed by a single radiologist.

Results: 3 patients had an apparent increase in tumour volume. Patient 1: 29yo female with a craniopharyngioma previously treated by surgery and radiotherapy. A slight increase in the cystic portion of the residual lesion was noted after 6 years, following which appearances were stable. Patient 2: 45 yo female with a suprasellar germ cell tumour. Apparent tumour recurrence was noted four years after commencement of GH. Biopsy demonstrated acellular fibrosis tissue only and GH was restarted. Patient 3: 54yo male with a dicentric (suprasellar and pineal) germ cell tumour. 19 months after commencement of GH his disease relapsed.

Conclusion: Overall, GH appears safe with respect to tumour recurrence over this time period in this patient group. Germ cell tumours remain a particular concern.