A case of pituitary adenoma associated with McCune-Albright syndrome

A 11-year-old boy presented with right temporal hemianopsia and was evaluated of a possible pituitary adenoma. At the age of six, he underwent surgery for facial deformities due to fibrous dysplasia. On admission, he had acromegalic features, was 170 cm tall, weighing 66 kg. The left side of his face was slightly deformed, and a café-au-lait spot was found on his right face. Endocrinologic examination revealed elevated basal level of serum GH (103.6 ng/ml, normal < 3 ng/ml) and PRL (259.1 ng/ml, normal < 30 ng/ml). Other endocrine functions were normal. CT showed hyperostosis of the right frontal, occipital, sphenoidal and maxillary bones. Magnetic resonance imaging (MRI) revealed a pituitary macroadenoma with intraadenomatous cyst. On the basis of physical, endocrinologic and neuroradiologic examination, our diagnosis was pituitary adenoma with McCune-Albright syndrome. Surgery was performed by subfrontal approach. By light microscopy, the pituitary tumor represented a typical acidophilic adenoma. Immunoreactivity for GH and PRL were evident in most of the adenoma cells. Double immunostaining for GH and PRL demonstrated the co-existence of the two hormones in a few adenoma cells. However the majority of cells expressed only one hormone. After surgery the right temporal hemianopsia improved. Postsurgical endocrinologic examination revealed reduction in basal serum GH and PRL levels. Administration of bromocriptine decreased blood PRL levels but it had a limited action on GH hypersecretion.