Endocrine Abstracts

Introduction: Disruption of the hypothalamic dopaminergic inhibitory control of prolactin (PRL) secretion results in hyperprolactinaemia. We have previously shown in a large series of patients with non-functioning pituitary macroadenomas that serum PRL virtually never exceeds 2000 mU/l in the absence of PRL elevating medications. Current data on the effect of other sellar/parasellar masses are limited.

Objective: To investigate the range of PRL values at presentation in adults with craniopharyngiomas (CR) and Rathke’s cleft cysts (RCC).

Patients and methods: All the patients who presented to our Department between January 1990 and September 2005 with histologically confirmed CR and RCC were studied.

Results: Forty-one patients with CR [median age 44 years (range 16–83), 28 males/23 females] and 8 with RCC [median age 45 years (range 23–88), 3 males/5 females] were identified. 2% (1/41) and 25% (2/8) of those with CR and RCC, respectively were on medications reported to raise serum PRL. All lesions were located in the sellar/parasellar area and had a suprasellar component. The median PRL in the total number of patients was 442 mU/l (range 12–6050) without a significant difference between the two groups [CR:median 437 mU/l (range 12–6050), RCC:median 679 (range 178–3731)]. Among those not on the above medications 96% (44/46) had PRL<2000, 4% (2/46) between 2000–3000 and 0% (0/46) >3000. The serum PRL of the 3 patients on drugs was 212 mU/l (verapamile/omeprazole), 3731 mU/l (sertraline/oestrogens) and 6050 mU/l (oestrogen implants). The median value of the remaining ones was 440 mU/l (range 16–2902).

Conclusions: In this series of patients with CRs or RCCs serum PRL>3000 mU/l was uncommon; such levels were found only in subjects treated with drugs capable of increasing PRL. Provided concomitant PRL elevating drugs are not being taken, PRL levels in pituitary stalk compression syndrome caused by CRs or RCCs do not exceed 3000 mU/l.