Abstract
A spontaneous brain tumor was found in a 46-week-old male AKR/J Sea mouse. The tumor occupied the forebrain, and invaded the nasal mucosa of nose along the nerve. The tumor cells showed a wide variety of sizes and shapes; round, polygonal, oval, and fusiform with eosinophilic cytoplasm. Bizarre giant cells with multiple nuclei, foci of necrosis and hemorrhage, and mitotic figures were common findings. According to these findings, the tumor was diagnosed as glioblastoma multiforme, a highly malignant astrocytic neoplasm. The tumor cells reacted negatively against the antibody for glial fibrillary acidic protein (GFAP), and had no glial filaments under ultrastructural examination. It is presumed that those immunocytochemical and ultrastructural findings show poor differentiation in this case.
