PAPILLARY TUMORS OF THE PINEAL REGION

Abstract

The pineal region is a rare intracranial site for metastasis. We report three patients initially considered to have metastatic papillary adenocarcinoma to the pineal region. On review, these papillary, keratin-positive neoplasms meet the criteria for papillary tumor of the pineal region (PTPR). These neoplasms occurred in three women (age range, 37-55 yr). Imaging studies demonstrated well-circumscribed lesions in the pineal region. All patients presented with obstructive hydrocephalus and symptoms attributable to hydrocephalus and tectal compression. All three patients underwent near total microsurgical resection of the pineal region neoplasm, followed by adjuvant radiotherapy. The two patients with long-term follow-up (56-60 mo) have remained clinically stable without evidence of local or distant recurrence. The first two patients were initially diagnosed as having papillary metastatic carcinoma of unknown origin. The third patient was treated after the recent description of PTPR and met the histopathological diagnostic criteria. Retrospective pathological review of the previous two patients resulted in designation as PTPR. The morphological features of the tumors in our series, along with the clinical presentations, are similar to those in the original description of the PTPR. Our findings agree with the original hypothesis that the cells composing the PTPR are similar to ependymal cells of the subcommissural organ, thus furthering the hypothesis that the PTPR derives from a specialized ependymocyte associated with the subcommissural organ. The two patients with long-term follow-up (56-60 mo) have remained clinically stable without evidence of local or distant recurrence.