Papillary tumor of the pineal region--a new pathological entity.

Papillary tumor of the pineal region has recently been proposed as a new, distinct clinicopathological entity. On the basis of the immunophenotypic and ultrastructural properties of these lesions, origin from specialized ependymocytes of the subcommissural organ was postulated. We present the third publication on a papillary pineal tumor and describe the morphological, immunohistochemical and ultrastructural features of this neoplasm. The patient was a young woman who presented with signs of raised intracranial pressure and Parinaud syndrome. Magnetic resonance imaging revealed a neoplastic lesion in the pineal region. She underwent surgical resection of the tumor through a midline infratentorial-supracerebellar approach. Papillary tumor of the pineal region represents a new, distinct clinicopathological entity. The differential diagnosis, possible histogenesis and management of these lesions are discussed.