ESPE Abstracts

Aim: We aimed to investigate the growth potential of pituitary microadenomas and cystic lesions < 10mm in children, and to evaluate how reproducible the measurements were on magnetic resonance imaging (MRI).

Design: Retrospective observational study.

Methods: 74 children were included < 18 years at first pituitary MRI, and diagnosed with a microadenoma (microadenoma producing ACTH, GH or TSH excluded) or cyst < 10 mm. The term probable microadenoma was used when the solid lesion was less distinct. Children with prolactinoma were included for testing of measurement accuracy. Pituitary lesion size at first and last MRI was reviewed by a neuroradiologist. All individual MRI examinations were re-evaluated by two radiologists.

Results: 74 children had a non-hormone producing microadenoma, probable microadenoma or cystic lesion, median age 12 years (range 3 – 17), 55 of those underwent repeated MRI, median number 3 (range 2 – 7), with a median follow-up time of 37 months (range 4 – 189). The most common symptoms were precocious puberty (n = 27, 36%) and growth disturbances (n = 22, 30%). Among these 74 children, 32 had hormonal treatment (10 GH and nine GnRH analogue). An additional 12 children with prolactinoma, median age 16 years (range 12 – 17), underwent repeated MRI, median number 5.5 (range 2 – 11), median follow-up time 73.5 months (range 26 – 120). None of the non-hormone producing microadenoma, probable microadenoma or cyst, with no hormonal deficiency increased significantly in size during follow-up (Table 1). One child with a cystic lesion developed hormonal deficits as the cyst grew, and another child had a prolactinoma that increased in size due to bad compliance to medication. Two reviewers agreed that no lesion could be identified in 38/269 MRI exams, in 51/231 (22%) there was disagreement about lesion location. They also disagreed in 34/460 (7%) MRI measurements to an extent that would have been considered progression in lesion size (> 2 mm).

Conclusion: Non-hormone producing pituitary microadenoma or cystic lesions in childhood with no hormonal disturbances show small, clinically irrelevant size variations that do not require intervention or extended follow-up with MRI.