Resolved GH excess and arginine vasopressin deficiency following pituitary apoplexy.

A 10-year, 8-month-old male presented with polyuria, polydipsia, and secondary nocturnal enuresis for 4 months following a severe headache. Initial fasting studies raised concern for partial arginine vasopressin deficiency (AVP-D). Brain magnetic resonance imaging revealed a possible pituitary adenoma vs artifact. His height was >99th percentile; he was prepubertal and growth charts demonstrated growth velocity >7.5 cm/year for the past 2 years. Additional testing showed markedly elevated IGF-1 and IGF-binding protein 3. He passed a water-deprivation test, ruling out AVP-D. He underwent a GH suppression test that revealed no suppression, suggesting GH excess. Repeat magnetic resonance imaging delineated a cystic pituitary lesion, most consistent with Rathke cleft cyst or hemorrhagic adenoma. Surgery was not recommended because the hematoma obscured visualization of any underlying tumor and evacuation could result in indiscriminate removal of the native gland. Serial imaging demonstrated continued retraction of the hematoma and tumor complex over 10 months. His AVP-D resolved, growth velocity slowed, and growth factors normalized over 13 months without intervention. Tall stature with increased growth velocity in prepubertal children should raise concern for GH excess. GH excess secondary to GH-secreting pituitary adenomas may spontaneously resolve if pituitary apoplexy occurs.