Recurrent symptomatic hypoglycemia with pancytopenia as a delayed presentation of radiation-induced panhypopituitarism with complete recovery after hormone replacement

Radiation therapy is widely used for intracranial and extracranial tumors management. Although three-dimensional planning and optimal radiation delivery, help to increase efficacy and minimizing the possible side effects but due to the increasing prevalence of brain tumors, whole of the brain especially the hypothalamo-pituitary unit receives significant doses of radiation resulting in radiation induced hypopituitarism and subsequent complications. Due to the fact that hypopituitarism induced by radiation is a concept of probability and increases with time, the first 5 years after exposure is the most common time for the possible radiation effects expressions although new hormonal deficiencies can occur as far as 20 years later. Up to now it is unlikely that the modern radiotherapy methods will be significantly associated with lower risk of radiation induced hypopituitarism so these patients need adequate lifelong monitoring as the pituitary failure can present almost at any time and with plenty of syndromes. Here we introduce a case with panhypopituitarism seven years after the last radiation therapy session presenting with recurrent hypoglycemia induced loss of consciousness.