Endocrine Abstracts

Case history & Management: A 36-year old lady of Lithuanian descent first presented in 2011 with secondary infertility due to hyperprolactinaemia of 1554 (N=0–500). Her MRI was normal and was started on Cabergoline which was stopped 5 months later when she became pregnant. She delivered normally but was thereafter lost to follow-up. She was referred back in 2014 with galactorrhoea and hyperprolactinaemia (6856) and MRI this time showed a 0.7 mm microprolactinoma. Cabergoline was restarted and 6 months later was stopped again when she became pregnant for the third time. Following this successful pregnancy, she returned to Lithuania and was lost to follow-up. In 2016, she resurfaced as an emergency at 34 weeks of pregnancy with headaches, bitemporal visual field loss and reduced foetal growth. Prolactin level was 119,965 and MRI showed a 3.1×3.2 cm macroprolactinoma with some apoplexy. Fortunately, she delivered soon after and neurosurgical intervention was not required. Except prematurity, baby remained unaffected. Since 2016, she remains on Cabergoline with undetectable (<40) prolactin levels, visual fields have recovered fully and serial MRI surveillance demonstrating gradual reduction of tumour mass.

Conclusions and points for discussion: This unique case demonstrates in a step-wise manner, the stimulatory effects of pregnancy on pituitary lactrotrophs. Our subject’s history suggests that every pregnancy led to a sequentlal increase in her lactrotroph cell mass as characterised by initiall a normal MRI and progressing to a microprolactinoma and culminating in a symptomatic macroprolactinoma. Current guidelines suggest that for hyperprolactinaemic patients with normal MRI or microprolactinoma, there is no utility of either biochemical, radiological or visual field surveillance during pregnancy. While this is applicable for the majority of such cases, this case example suggests that endocrinologists should still exercise caution and arrange for follow-up surveillance in such patients following completion of pregnancy. If future pregnancies are aspired, then it is important to have pre-pregnancy counselling to discuss potential risks including macroadenomatous transformation, growth retardation and consequences of pituitary insufficiency.