Endocrine Abstracts

A 34-year-old lady presented with polyuria and polydipsia 21 months post Caesarian delivery of twins. She had no peri-partum complications but immediately post partum, had noted increased thirst – she noted a particular strong craving for cold soft drinks. She had obesity and a positive family history for diabetes but screening for diabetes was negative. She also noted cessation of her menses. A gynaecologist who assessed her found her to have mild hyperprolactinaemia for which bromocriptine was initiated with normal resumption of periods.

Four months later, she presented with blurring of vision and worsening polyuria (in excess of 7 l a day). She was referred for endocrine evaluation and found to have raised random blood glucose (26.5 mmol/l). Despite optimal glycaemic control, her symptoms of polyuria and polydipsia persisted. Investigations revealed an overnight fluid deprived serum osmolality of 320 mmol/kg and urine osmolality 244 mmol/kg. MRI pituitary revealed a moderate thickening of the pituitary stalk. Evaluation for anterior pituitary hormone dysfunction revealed no abnormalities. She was commenced on nasal minirin 10 mcg BD with good symptomatic relief.

The diagnosis of lymphocytic hypophysitis was considered in view of the typical presentation and investigations were done to exclude other causes of a thickened pituitary stalk. After careful discussion with the patient, it was decided to observe her with close endocrine follow up and imaging studies.

Over the next few years, she developed sequential and progressive anterior pituitary hormone deficiencies requiring replacement therapy – hypogonadism, hypocortisolaemia and hypothyroidism 2, 3 and 4 years, respectively. Serial MRI scans showed evolution of the thickened pituitary stalk to enlargement of the pituitary gland and final resolution of the lesion.

This paper will illustrate the evolving sequential MRI changes over the 14 years of follow up, and complete resolution of a large pituitary mass.