Endocrine Abstracts

Case: This 23-year-old lady initially presented in 2013 with headaches, galactorrhoea and secondary amenorrhoea. Visual fields were normal to confrontation. Prolactin levels were elevated at 3028miu/l. MRI pituitary revealed a 14x13x15mm adenoma pushing the pituitary stalk posteriorly, and compressing the left side of the optic chiasm.

Initial Management: Cabergoline was commenced (250mg twice weekly), with good clinical response. Galactorrhoea ceased and her menstrual periods returned. Prolactin levels reduced to within the normal range (277miu/l). Repeat MRI pituitary following six months of treatment (April 2014) revealed reduction in size of the previous macroadenoma (9x8x10mm).

Clinical Course: In December 2018, this lady became pregnant and she stopped taking Cabergoline at the time of a positive pregnancy test. Visual fields were monitored throughout pregnancy with nil concerns. Following delivery, she recommenced Cabergoline. Repeat MRI Pituitary in June 2022, whilst continuing Cabergoline, revealed further interval reduction in the left sided adenoma (7x8x9mm), with no optic nerve compression or cavernous sinus invasion. She became pregnant again in October 2022 and stopped Cabergoline. At 16 weeks pregnant, severe left sided headaches commenced. Initially managed with analgesia (paracetamol and dihydrocodeine), but at 22 weeks inpatient admission was required due to persistent debilitating headaches. She was unable to complete visual field assessment due to vasomotor symptoms in her left eye. MRI Pituitary repeated as an inpatient, highlighted an increase in size of the left sided pituitary adenoma (8x12x11mm), with left sided cavernous sinus involvement. Cabergoline was recommenced due to symptomatic trigeminal irritation and headaches much improved with this therapy. This was successfully continued throughout pregnancy and post-partum, as this lady did not plan to breastfeed.

Conclusion: This case highlights Macroprolactinoma management challenges during pregnancy. Following an initially uncomplicated first pregnancy, re-initiation of dopamine agonist therapy was required during her second pregnancy.