Contributed by Christian Mawrin, MD 1,4, Rainer Hahne 2, Cordula Scherlach, MD 3 , Elmar Kirches, PhD 1 , and Knut Dietzmann, MD 1
Departments of 1Neuropathology, 2Neurosurgery, 3Radiology, 4Psychiatry
University of Magdeburg Medical School; D-39120 Magdeburg, Germany
Published on line in June, 2004
Over the past year, this man in late sixties had complained about progressive weakness of concentration and memory disturbances, associated with word finding difficulties. Upon admission, neurological examination revealed a distinct paresis of the right arm and leg. Knee and ankle reflexes were brisk on the right side and reduced on the left side. Additionally, anemia and reduced stride length due to known Parkinsonīs disease were noted. MRI examination revealed an extra-axial, parasagittal tumor 3cm in diameter located in the left frontoparietal region. The lesion was isointense on T1 and T2-weighted images, with homogeneous signal enhancement after contrast medium application (Figure 1A).
Five years ago, an extracerebral tumor located in the same region, with radiographic appearance comparable to the present tumor had been totally removed (Figure 1B).
In the present recurrent tumor, the histological picture was dominated by sheets of large rounded pleomorphic tumor cells with abundant eosinophilic cytoplasm and eccentric nuclei. Cytoplasmic inclusions were frequent; occasionally, multinucleated tumor cells were seen (Figure 2A). Neither necroses nor brain invasion were observed. Mitotic figures were absent, and the MIB-1 labeling index (LI) as determined from 10 consecutive high-power fields was 3.0 %. An example for the MIB-1 staining is shown in Figure 2B. Meningothelial lobules were scarce, and regions with fibroblastic appearance were absent. There were no psammoma bodies. Moderate immunoreactivity for EMA was found, and some LCA positive lymphocytes were scattered through the tumor. Additionally, strong cytoplasmic immunoreaction for vimentin within the large tumor cells was observed (Figure 2C).
In the first tumor removed five years ago, regions of meningothelial tumor cells were mixed with areas composed of spindle-shaped cells arranged in parallel fascicles (Figure 3A). No histological criteria of malignancy were observed, and the MIB-1 proliferation index did not exceed 1% in any region of the tumor sample. Mitotic figures were absent. However, small islets of larger tumor cells with eccentric nuclei and eosinophilic cytoplasm and strong immmunoreactivity for vimentin were already present in this sample (Figure 3B, 3C,).