Papillary tumor of the pineal region in a 15-month-old boy.

The papillary tumor of the pineal region (PTPR) is a distinct entity that is particularly rare in the pediatric population. The authors document the youngest reported patient with this clinicopathological entity to date. A case of PTPR in a 15-month-old boy is described. Initially thought to be a tectal glioma, the tumor was later identified as a pineal region tumor after demonstrating growth on routine imaging. Diagnosis of PTPR was established by histopathological evaluation of biopsy samples, which revealed papillary, cystic, and solid tumor components. The patient's postoperative course was complicated by tumor growth despite several debulking procedures and chemotherapy, as well as persistent hydrocephalus requiring 2 endoscopic third ventriculostomies and eventual ventriculoperitoneal shunt placement. After a 15-month follow-up period, the patient has received proton-beam therapy and has a stable tumor size. The PTPR is a recently described tumor of the CNS that must be included in the differential diagnosis of pineal region masses. The biological behavior, prognosis, and appropriate treatment of PTPR have yet to be fully defined.