Yalda Nilipour - Pediatric pathology research center, research institute for children health, Mofid hospital, School of medicine, Shahid Beheshti university of medical sciences, Tehran, Iran
Maryam Deldadeh Moghaddam - Pathology departement, School of medicine, Shahid Beheshti university of medical sciences, Tehran, Iran
Hasanreza Mohammadi - Surgery departement, School of medicine, Shahid Beheshti university of medical sciences, Tehran, Iran
Maryam Parvizi - Pediatric pathology research center, research institute for chilren health, Mofid hospital, School of medicine, Shahid Beheshti university of medical sciences, Tehran, Iran

Pineal anlage tumor is a rare malignant pineal region neoplasm with both neuroepithelial and ectomesenchymal components. Due to rarity of this tumor full understanding of its biologic behavior is incomplete and it is still not listed as separate entity in 2016 WHO classification of central nervous system tumors. We report this tumor in a 10 month- old girl with enhancing tumor of posterior aspect of pineal gland presenting as a tumor of third ventricle. We received fresh specimen for intraoperative consultation considering probability of germinoma. Frozen section diagnosis of malignant small round cell tumor was reported. In permanent sections a malignant neoplasm was seen composed of primitive neuroepithelial component and focal ectomesenchymal component consists of lobules of cartilage and adipose tissue mixed with heavily pigmented melanin containing epithelioid cells arranged in nests and tubules. No endodermal or cutaneous derivatives were seen. This case is presented due to its rarity and its important differential diagnosis with teratoma.

Pineal anlage tumor, pineoblastoma, teratoma, pineal, brain tumor