Species: Rat Strain/breeder: CRL:WI (GLX/BRL/HAN)/ CR Sex: Male Age: 18 months Study type: Carcinogenicity study Treatment: Control animal Animal status: Survivor Clinical findings:   Organ(s): Nasal cavity Macroscopic finding(s): Mass, left medial lobe, cystic, 10 mm x 5 mm, yellow-white Staining: H&E

Fig. 1 (151k)

Abstract

J. WALTER

BASF AG, Department of Product Safety, Regulations, Toxicology and Ecology, GV/T, Z 470, 67056 Ludwigshafen, Germany

Key words: nasal cavity, brain tumour, astrocytic, rat

In a male control rat in a carcinogenicity study, an intranasal mass was found at scheduled sacrifice. A similar but smaller protrusion was detected at the rhinencephalon. The histological examination showed a marked anaplasia, increased cellularity of poorly differentiated, fusiform, round to pleomorphic cells, multifocal areas of necrosis as well as proliferation of vascular endothelium. Most parts of the tumour were immunoreactive for GFAP and S100, but negative for cytokeratin. On this basis and according to the WHO classification a diagnosis of glioblastoma was made.