2010 Volume 32 Issue 6 Pages 518-522
Background. Papillary type squamous cell lung carcinoma is a variant of squamous cell carcinoma and a rare disease which must be distinguished from isolated papilloma. We experienced a case of papillary type squamous cell carcinoma which was difficult to distinguish from isolated papilloma on biopsy. Case. In a man aged 68, an abnormal shadow in the right upper lung field was found on a chest X-ray film with a soft tissue density mass lesion in the right upper lobe. Peripheral obstructive pneumonia was also confirmed by chest CT. Both examinations were performed due to fever onset in November 2008 during treatment for alcohol dependency. The patient was referred to our hospital for further examinations. His smoking history was 20 cigarettes per day for 50 years. Upon bronchoscopy for confirmation of a central lesion, a polypoid mass with a granular surface was observed protruding into the right upper lobe. Even though it was diagnosed as atypical papillary type squamous papilloma on initial biopsy, the affected part was removed by a high-frequency snare since atypical histology was also observed and therefore we could not definitively exclude a cancer. The tumor was located near the orifice of B^3 bronchus and it developed from the orifice toward the central side, the final tissue diagnosis was determined to be papillary type squamous cell carcinoma. Since then we have been monitoring the patient without prescribing additional treatment due to social factors. Conclusion. A sample of the whole tumor based on high-frequency snare excision is required to diagnose papillary type squamous cell carcinoma, since it is difficult to distinguish from isolated papilloma.