BACKGROUND: Mucoepidermoid carcinoma is a relatively uncommon form of lung cancer and has generally been viewed as a low grade malignant tumor. The present study was undertaken to establish a clinicopathological characterization of patients with this cancer who were treated surgically 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 the central type of carcinoma was 67%, while the 4-year survival rate for 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 all had a grade 1 central type tumor. CONCLUSIONS: These results suggest that mucoepidermoid carcinoma of the lung should not be viewed uniformly as a low grade malignant tumor, but that this tumor can sometimes be highly malignant with a poor prognosis. Since this tumor is often difficult to distinguish from adenosquamous carcinoma, and because accurate distinction between these two types of tumor seems to be essential for establishing a prognosis, there is an urgent need for a valid pathological method for differential diagnosis of mucoepidermoid carcinoma.
BACKGROUND:Mucoepidermoid carcinoma is a relatively uncommon form of lung cancer and has generally been viewed as a low grade malignant tumor. The present study was undertaken to establish a clinicopathological characterization of patients with this cancer who were treated surgically 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 the central type of carcinoma was 67%, while the 4-year survival rate for 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 all had a grade 1 central type tumor. CONCLUSIONS: These results suggest that mucoepidermoid carcinoma of the lung should not be viewed uniformly as a low grade malignant tumor, but that this tumor can sometimes be highly malignant with a poor prognosis. Since this tumor is often difficult to distinguish from adenosquamous carcinoma, and because accurate distinction between these two types of tumor seems to be essential for establishing a prognosis, there is an urgent need for a valid pathological method for differential diagnosis of mucoepidermoid carcinoma.