Forty-four previously diagnosed surgical biopsy specimens of oligodendroglioma 
with calcification from the file of Veterans General Hospital-Taipei between 
1977-1985 form the base of this study. Thirty-two patients (72.8%) had varied 
degree of calcification deposits in tumor parenchyma related to blood vessels 
while 12 patients (27.2%) in tumor parenchyma unrelated to blood vessels. Ten 
patients (22.7%) disclosed calcification at the vicinity of tumor tissue. 
Histochemical studies of the calcified deposits revealed no trace minerals other 
than calcium and iron. Electron microscopic examination of the calculi showed 
membrane-bound vesicles and radially precipitated crystals that simulated 
hydroxyapatite of psammoma body in meningioma. There was no statistically 
significant correlation between the demise or recurrence of patients and the 
calcification of tumor when Chi-squared test was applied.