pineal papillary tumors

Neuroepithelial papillary tumor of the pineal region (PTPR) has been defined as a distinct entity that is increasingly being recognized, with 96 cases now reported. This tumor shares morphologic features with both ependymomas and choroid plexus tumors. PTPR is characterized by an epithelial-like growth pattern in which the vessels are covered by layers of tumor cells forming perivascular pseudorosettes. These tumors exhibit various combinations of papillary and solid architecture, making the differential diagnosis of PTPR difficult to establish.

Immunochemistry

Claudin-1 and claudin-3, but not claudin-2, were expressed in PTPRs and in the fetal subcommissural organ, potentially the origin of this tumor. (22588068)

In contrast, all 3 claudins were expressed in choroid plexus papillomas. Claudin expression may help in the diagnosis of PTPRs and can be used in combination with other markers, such as CK18, NCAM, E-cadherin, MAP-2, and Kir 7.1. (22588068)

Reference

 Histopathologic and ultrastructural features and claudin expression in papillary tumors of the pineal region: a multicenter analysis. Fèvre Montange M, Vasiljevic A, Bergemer Fouquet AM, Bernier M, Champier J, Chrétien F, Figarella-Branger D, Kemeny JL, Lechapt-Zalcman E, Michalak S, Miquel C, Mokthari K, Pommepuy I, Quintin Roué I, Rousseau A, Saint-Pierre G, Salon C, Uro-Coste E, Varlet P, Kratzer I, Ghersi-Egea JF, Jouvet A. Am J Surg Pathol. 2012 Jun;36(6):916-28. PMID: 22588068