Résumé
<p><b>OBJECTIVE</b>To study the clinicopathologic features of papillary tumor of the pineal region (PTPR).</p><p><b>METHOD</b>Three hundred and eighty six cases of pineal region and posterior third ventricle tumors, two newborn and two adult pineal glands were analyzed by HE, PAS and immunohistochemistry of 16 antibodies (EnVision method).</p><p><b>RESULTS</b>Five cases of PTPR were diagnosed with mixed papillary features and densely cellular areas, and included one recurrent case. In the papillary areas, the vessels were lined by one or several layers of cuboidal/columnar cells; the vessel wall was hyalinized. In the densely cellular areas, sheets or nests of tumor cells were seen. The tumor cells of these five cases were immunoreactive to CK, CK8/18, synaptophysin, MAP2, nestin, S-100, and vimentin. Four cases were immunoreactive to NSE and CgA; and 2 cases were immunoreactive to NF. All five cases were negative for EMA, CK5/6, CEA, and NeuN. Ki-67 labeling index ranged from 1% to 6%.Three patients were alive, and the recurrent one died.</p><p><b>CONCLUSIONS</b>PTPR occurs in patients with over a wide age range, from children to adults, and is more commonly found in male than female. PTPR is composed of both papillary and solid areas, characterized by epithelial cytology, and needs to be differentiated from ependymoma. PTPR may originate from the specialized ependymocytes of the subcommissural organ. The prognostic factors are early diagnosis, complete surgical resection and radiotherapy.</p>