RECURRENT ANAPLASTIC GANGLIOGLIOMA - PATHOLOGICAL CHARACTERIZATION OFTUMOR-CELLS - CASE-REPORT

A total resection of a left frontal lobe tumor in a 26-year-old man re vealed differentiated ganglioglioma with small foci of atypical glial cells exhibiting mild atypia. Six and one-half years later, a large, w ell-demarcated tumor recurred; at that time, histological analysis rev ealed both typical ganglioglioma and highly cellular anaplastic areas, the latter predominating. Although the patient subsequently underwent total and subtotal resections, radiation therapy, and chemotherapy, t umors continued to recur at progressively shorter intervals and he die d at the age of 35 years. Biopsies of tissue obtained at the last thre e resections and the autopsy revealed only anaplastic tumor cells. Rou tine histological examinations indicated that these tumors were unifor mly composed of undifferentiated cells. However, pathological studies using immunohistochemical analysis, electron microscopy, and immunoblo t analysis demonstrated that a small number of recurrent anaplastic ce lls had astrocytic features. Results of Ki-67/MIB-1 labeling and silve r nucleolar organizer region counts for those cells were high for glia l tumors. A retrospective study of the initial tumor showed slightly h igh MIB-1 labeling for atypical glial cells. This case is characterize d by pathological findings of recurrent tumors that correspond to an u nusual form of malignant glioma exhibiting slight astrocytic different iation. The present case suggests that a longer follow-up period (> 5 years) is necessary in cases of ganglioglioma with mild atypia and tha t careful examinations, including proliferating potential analysis of initial tumor cells, could be important for the diagnosis and treatmen t of ganglioglioma.