Science Publications

BACKGROUND: Absolute criteria for grading oligodendrogliomas are somewhatpoorly defined in contrast to those for grading astrocytic tumors, and cytologic features ofanaplastic oligodendrogliomas have been poorly described. CASE: A 63-year-old man presented with atoppling gait. Radiologic examination revealed a 7-cm mass with calcifications in the right frontallobe. Intraoperative smears of the tumor showed hypercellular, loosely cohesive cell clusters andsingle cells with nuclear pleomorphism, numerous apoptotic cells and no discernible fibrillaryprocesses. Many bland-looking round cells with cyanophilic cytoplasm and eccentrically locatednuclei, so-called minigemistocytes, were intermingled among atypical cells. Cryostat sections showedcellular nests consisting of tumor cells with oval nuclei and clear cytoplasm. These cells wereproliferating in the finely reticulated vascular stroma, and the tumor had an infiltrative marginwith areas of focal necrosis and numerous calcifications. The diagnosis of anaplasticoligodendroglioma, World Health Organization grade 3, was made, and the results of fluorescence insitu hybridization (chromosome 1q deletion) supported the diagnosis. CONCLUSION: Intraoperativediagnosis of anaplastic oligodendroglioma may not be easy but is possible with judiciousconsideration of several features: high cellularity, no fibrillary processes, nuclear atypia,pleomorphism, abundant apoptotic cells, occasional mitotic figures, coagulative necrosis,endothelial hyperplasia and characteristic conspicuous minigemistocytes.

Mitsuhashi,T　Shimizu,Y　Ban,S　Ogawa,F　Matsutani,M　Shimizu,M　Hirose,T
Department of Pathology, Saitama Medical School, Saitama, Japan.mitsut@mail.tains.tohoku.ac.jp

Diagnostic　 Undifferentiated　 Neoplasms　 Cancer cells grading systemIntraoperative

I***ssue 4,5,6 finished.