Wanida Phatan M.D., Poonsiri Srinawat M.D., Sakda Waraasawapati M.D.
Department of Pathology, Faculty of Medicine, KhonKaen University
Pineal region tumors are rare and heterogeneous including germ cell tumors, pineal parenchymal tumors and
neuroepithelial tumors. Amongthe pineal region tumors, germ cell tumorssuch as germinoma and teratoma are
the most common, followed by pineal parenchymal tumors. We have discusseda case of 20-year-old woman
who has clinical recurrent pineal gland tumor of unknown pathological diagnosis. Histologic fi ndings of the
tumor reveal ectomesenchymal components including cartilage, fat, glial cells, ganglion cells and also has
focal simple columnar epithelium with apical mucin and basal nuclei that suspicious for endodermal
component. No epidermis or skin adnexa is present. We favor the diagnosis of teratoma, however, it should be
distinguished from pineal anlage tumor. The later is a pineal tumor with neuroepithelial and ectomesenchymal
differentiation but without endodermal differentiation. It is extremely rare and has a very poor prognosis.
In this case, it is diffi cult to histologically differentiate between teratoma and pineal anlage tumor due to less
ectodermal differentiation and questionable endodermal component.