Endocrine Abstracts

Although double adenomas may be present in 1% of autopsy pituitaries, in patients with pituitary disease they are extremely rare. In previously reported surgical series an incidence of 0.37–1.64% has been observed. We report a 55 year old lady with features suggestive of acromegaly and a double pituitary adenoma on MRI. The diagnosis of acromegaly was confirmed by an elevated serum IGF-I and a nadir growth hormone of 10.3 mU/l during a 75 g oral glucose tolerance test. Other baseline pituitary hormones and serum calcium were normal. She had no symptoms suggestive of hypoglycaemia, anaemia or diarrhoea. There was no family history. MRI pituitary revealed two clearly separated and discrete microadenomas – a left sided 8 mm lesion along with a 6 mm right-sided adenoma and no optic chiasm involvement. She is shortly to commence somatostatin analogue therapy.

In previous reported series of double pituitary adenoma, the majority were encountered in the clinical context of acromegaly with both tumours having functional capability, although individual tumours may be from 2 separate adenoma groups (GH-PRL-TSH group and FSH/LH group). Cases of MEN-1 and familial pituitary tumours unrelated to MEN-1 may be over-represented in the series reported to date, suggesting that genetic abnormalities may be involved in their pathogenesis. Management of double adenomas is challenging since there is a higher risk of surgical failure and a high risk of iatrogenic hypopituitarism. In the present case the choice rests between attempted cure via a one step or two step surgical approach or the use of a somatostatin analogue, or even pre-treatment with the latter before surgery. However, the effect of somatostatin analogue therapy in this clinical context has not previously been reported.