Abstract

Choroid plexus carcinoma (CPC), a frankly malignant epithelial neoplasm derived from choroid plexus epithelium, is a rare tumor with a predilection for infants and children. It may be difficult to histologically differentiate it from choroid plexus papilloma, anaplastic ependymoma, medulloblastoma, germ cell tumors, and metastatic carcinoma. We examined two cases of CPC. One is a 12-month-old boy, and the other is a 13-month-old boy. Both patients present lateral ventricular masses with extensive hydrocephalus. Histologically, both tumors show papillary growth in most area, and focal solid growth. The tumor cells show marked nuclear pleomorphism and frequent mitoses on squash and hematoxylin-eosin slides. Immunohistochemically, both tumors are positive for cytokeratin, vimentin, and S-100 protein; but they are negative for glial fibrillary acidic protein, -fetoprotein, and placental alkaline phosphatase. Both tumors show diffuse and strong positivity for p53. The MIB-1 labelling index is 23.6% and 15.82%, respectively. We report two cases of typical CPC, and we briefly discuss differential diagnosis with review of literatures.

• Keywords: Brain;Choroid plexus neoplasms;Diagnosis;Differential;Immunohistochemistry