A Case of a Small Lesion of Squamous Cell Carcinoma of the Peripheral Lung Diagnosed by Positive Findings on Sputum Cytologic Examination

Abstract

Background. We report a case of a small lesion of squamous cell carcinoma of the peripheral lungdiagnosed two years after sputum cytology indicated malignancy.Case. A 77-year-old man had positive findings on sputumcytology mass screening, but no abnormality was found on investigation. Chest radiography and computed tomographyperformed two years later revealed a 12mm nodule in the S³ segment of the right upper lobe. Bronchoscopyof the area that could be visualized and selective brushing cytology of each segmental bronchus were negative. The nodulewas estimated to be located in the sixth bronchial branch or a more peripheral region, and percutaneous biopsy ofthe nodule aided by computed tomography was performed, resulted in a diagnosis of squamous cell carcinoma. He subsequentlyreceived stereotactic radiation therapy (60 Gy in 8 fractions). During four years of follow up, sputum cytologyhas continued to be negative.Conclusion. Positive findings on sputum cytologic examination in the present case weredue to a small lesion of squamous cell carcinoma of the peripheral lung.