Radiation-induced Undifferentiated Malignant Pituitary Tumor After 5 Years of Treatment for Cushing Disease.

The occurrence of a second neoplasm possibly constitutes an adverse and uncommon complication after radiotherapy. The incidence of a second pituitary tumor in patients irradiated for adrenocorticotropic hormone secreting pituitary adenoma is rare. We report a case of a 40-year-old female with Cushing disease who underwent surgical management followed by radiotherapy. After 5 years of initial treatment, an increase in tumor size was evident at the same location, with a significant interval growth of the parasellar component of the lesion. Histology revealed an undifferentiated highly malignant sarcoma. In the span of next 2 years, the patient was followed with 2 repeat decompression surgeries and radiotherapy because of significant recurrent compressive symptoms by locally invasive malignant tumor. Despite the best efforts, the patient remained unresponsive to multiple treatment strategies (eg, surgical resections and radiotherapy) and succumbed to death.