CLINOCOPATHOLOGIC STUDY OF MUCOEPIDERMOID CARCINOMA OF THE LUNG

Background. Mucoepidermoid carcinoma is a relatively uncommon form of lung cancer and has generally been viewed as a low grade malignant tum or. The present study was undertaken to establish a clinicopathologica l characterization of patients with this cancer who were treated surgi cally at Kanazawa University Hospital. Methods. Between 1973 and 1975, 10 patients with mucoepidermoid carcinoma were surgically treated in our department, Results. The 10-year survival rate after surgery for t he central type of carcinoma was 67%, while the 4-year survival rate f or the peripheral type was 25%, When the survival rates were analyzed in terms of Conlan's grades, grade 1 cases had a 10-year survival rate of 80%, while the 4-year survival rate for grade 2 and 3 cases was 20 %. The four patients who survived 5 years or more following surgery al l had a grade 1 central type tumor. Conclusions. These results suggest that mucoepidermoid carcinoma of the lung should not be viewed unifor mly as a low grade malignant tumor, but that this tumor can sometimes be highly malignant with a poor prognosis. Since this tumor is often d ifficult to distinguish from adenosquamous carcinoma, and because accu rate distinction between these two types of tumor seems to be essentia l for establishing a prognosis, there is an urgent need for a valid pa thological method for differential diagnosis of mucoepidermoid carcino ma.