Head and neck manifestations of an undiagnosed McCune-Albright syndrome: clinicopathological description and literature review.

Craniofacial fibrous dysplasia, characteristic of McCune-Albright syndrome (MAS), is usually present in patients with MAS-related acromegaly. We report here the first case of a patient with an undiagnosed MAS presenting with an acute hydrocephalus. A 21-year-old male with gigantism and craniofacial fibrous dysplasia consulted for rapidly progressive headache. An acute obstructive hydrocephalus due to a 39 × 35-mm cystic lesion in the third ventricle was discovered and operated, obtaining hydrocephalus resolution. Pathology described a colloid cyst material and a growth hormone-secreting pituitary adenoma. Genetic study revealed the mosaic GNAS R201H mutation in the pituitary tissue, confirming a MAS diagnosis. Adequate hormonal control was achieved postoperatively. Our results suggest that long-term untreated growth hormone excess in patients with MAS-related craniofacial fibrous dysplasia might end compromising cerebrospinal fluid flow. A prompt diagnosis and coordinated multidisciplinary treatment may help to avoid long-term deleterious impact of hyperfunctioning endocrinopathies in these patients.