title: Pineal parenchymal tumor of intermediate differentiation with marked elevation of MIB-1 labeling index.
abstract: We report a case of pineal parenchymal tumor (PPT) in an 11-year-old girl. Brain magnetic resonance imaging (MRI) revealed a large tumor (48 mm) located in the pineal region with heterogeneous enhancement after gadolinium administration. The patient underwent tumor removal with craniotomy; only partial tumor resection could be performed because of massive intratumoral bleeding. Histopathological examination of the tumor showed lobular proliferation of round cells with moderate atypia. Cellularity varied by area, and focal Homer Wright rosettes were identified. Examination of tumor cells revealed a few mitoses (two mitotic figures per 10 high-powered fields), and immunohistochemical staining revealed positivity for synaptophysin, slight positivity for neurofilament protein (NFP) with antibody clone 2F11, and strong positivity for NFP with clone NF-M+H. The pathological diagnosis was pineal parenchymal tumor of intermediate differentiation grade II according to World Health Organization criteria despite a high (22%) MIB-1 labeling index (LI). The patient had a favorable clinical course after an intensified chemotherapy regimen designed for pineoblastoma and radiotherapy administered to the entire neuraxis, followed by stereotactic radiotherapy. In conclusion, MIB-1 LI could be a useful tool for deciding therapeutic strategies for PPT treatment when there is a discrepancy between clinical findings and pathological grading.
authors.affiliation: Division of Pediatric Neuro-Oncology, Department of Neuro-Oncology/Neurosurgery, Saitama Medical University International Medical Center, Yamane 1397-1, Hidaka, Saitama 350-1298, Japan. kfukuoka@saitama-med.ac.jp
authors.forename: Kohei
authors.initials: K
authors.lastname: Fukuoka
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sasaki
authors.forename: Takaaki
authors.initials: T
authors.lastname: Yanagisawa
authors.forename: Tomonari
authors.initials: T
authors.lastname: Suzuki
authors.forename: Kenji
authors.initials: K
authors.lastname: Wakiya
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Adachi
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Mishima
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Fujimaki
authors.forename: Masao
authors.initials: M
authors.lastname: Matsutani
authors.forename: Ryo
authors.initials: R
authors.lastname: Nishikawa
mesh_terms: D002648:Child; D003131:Combined Modality Therapy; D003399:Craniotomy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D016900:Neurofilament Proteins / Q000378:metabolism; D019635:Neurosurgical Procedures / Q000379:methods; D010871:Pinealoma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D016634:Radiosurgery; D016708:Synaptophysin / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D019394:Ki-67 Antigen; D016900:Neurofilament Proteins; D016708:Synaptophysin