Endocrine Abstracts

Background: Pituitary hyperplasia is a relatively common yet frequently overlooked condition which can occur in both physiological and pathological states. Pregnancy is one of the most common conditions associated with physiological pituitary enlargement.

Case Presentation: 22-year-old normally fit and well lady presented to AMU (acute medicine unit) with a week history of headache and 10-month history of amenorrhoea following cessation of combined contraceptive pill. Pregnancy test done at home was negative and noted to have hyperprolactinemia of 1573 mU/l as investigated by her GP. Neurological examination was normal with normal visual acuity. Her repeat prolactin during the admission came back as 2097 mU/l and hence an MRI was carried out which reported a 9.5 mm pituitary enlargement proximal to but not compressing the optic chiasm. The rest of her pituitary hormone profile was normal. She was re-admitted to AMU a week later with increasing headache and blurred vision and diplopia but Goldman test confirmed no bitemporal field loss. CT head was done to rule out pituitary apoplexy which showed unchanged appearance from the previous scan. The repeat prolactin was 4953 mIU/l. After being seen by endocrinology team advising to repeat pregnancy test, she was found to be pregnant and confirmed by a dating scan. A diagnosis of pregnancy induced pituitary hyperplasia was made. MRI pituitary one year post-partum showed complete resolution along with normalisation of prolactin level.

Conlusions: It is very important to look for physiological causes like pregnancy while investigating for pituitary enlargement and high level of suspicion should be kept even with a negative home pregnancy test. An early and correct diagnosis could have prevented unnecessary exposure to radiation during pregnancy.