CLINICAL ANALYSIS OF SOLITARY PULMONARY NODULES BEFORE AND AFTER RESECTION OF PREVIOUS MALIGNANCY

Abstract

The differential diagnosis is important for treatment of a solitary pulmonary nodule. Differential diagnosis among primary lung cancer, lung metastasis and benign lung tumor is essential in patients with a history of previous malignancy. For differential diagnosis, it is important to clarify incidences of pathological characteristics of pulmonary solitary nodules. We evaluated the clinical and pathological characteristics of 56 cases (male : 38, female : 18, mean age : 65.3 years old) of solitary pulmonary nodules which were found before and after resections of previous malignancy, and were resected at our hospital from January 2000 to June 2003. The average observation period from the operation for the previous malignancy to the removal of a solitary pulmonary nodule was 33.5 months. The most frequent primary site of the previous malignancy was the large intestine (19 cases), followed by the stomach (18 cases), the breast (7 cases) and the others (12 cases). The pathological examination showed that 11 cases (19.6%) were of benign tumor and 45 cases (80.4%) were of malignancy, including 30 cases (53.6%) of primary lung cancer and 15 cases (26.8%) of pulmonary metastasis. A solitary pulmonary nodule developing in a patient with previous malignancy is most likely to be pulmonary metastasis. However, our results indicate that primary lung cancer occurs more often than pulmonary metastasis even in a patient with previous malignancy. Caution should be paid to that primary lung cancer can occur more than same as often as pulmonary metastasis even in a patient with previous malignancy.