Clinicopathological investigation of pulmonary pleomorphic carcinoma.

BACKGROUND Pleomorphic carcinoma is an uncommon malignant tumor of the lung. As there are few large-scale studies of patients with pleomorphic carcinoma, the clinical characteristics and behavior of the disease have been unclear until now. In this study, we investigated the clinicopathological findings and prognosis of 21 patients with pleomorphic carcinoma. PATIENTS AND METHODS We identified 930 cases of pulmonary carcinoma in which the patient underwent a lung resection in our institute between January 1999 and June 2007. Of those patients, 21 (2.6%) were diagnosed with pleomorphic carcinoma as determined by the three pathologists in our institute. RESULTS The 21 study subjects consisted of 18 male and 3 female patients. The locations of the lesions were as follows: 13 cases, right upper lobe; 5 cases, left upper lobe; 2 cases, right lower lobe; and 1 case, left lower lobe. The mean diameter of the tumor in this series was 55.2 mm (17-100 mm). As for the pathological stage, four cases were stage IA, seven cases were stage IB, five cases were stage IIB, two cases were stage IIIA, and three cases were stage IIIB. The overall 5-year survival rate was 80.0%. There were no significant differences between the symptomatic group and the asymptomatic group, or between the p-factor positive group and the p-factor negative group. On the other hand, there was a significant difference in the disease-free survival rate between the node negative group and the node positive group, and there was also a significant difference in the overall survival rate between the curative operation group and the non-curative operation group. CONCLUSIONS In this clinical study, the presence of lymph node metastasis and the treatment by a curative resection of the tumor were the most important prognostic factors for pulmonary pleomorphic carcinoma. However, further investigation of a large number of cases is needed in order to gain a clearer understanding of the clinical characteristics and behavior of pleomorphic carcinoma.