Abstract
Abstract-Background. Central bronchial squamous cell carcinomas occasionally form endobronchial masses, and also tend to be difficult to resect completely because of their invasive growth with severe local extension in the advanced stages. Case. A 58-year-old man was admitted to our hospital with an abnormal mass shadow in the right lung discovered upon routine check-up. Bronchoscopy demonstrated an endobronchial tumor, that obstructed the right upper trunk. The tumor was diagnosed as squamous cell carcinoma by transbronchial biopsy and right upper lobectomy was performed. Intraoperative frozen section demonstrated a residual in situ carcinoma on the bronchial stump, and complete resection could be performed by additional bronchial resection. The tumor extended along the bronchial wall with intraepithelial spreading at its invasive front, and also showed exophytic growth forming an arborescent mass measuring 4.5cm, which filled the bronchial lumen. Histologically, the tumor was well differentiated squamous cell carcinoma proliferating in a papillary pattern with fibrovascular stroma. Despite being large, the extrabronchial invasive tendency was low and most of the tumor remained within the bronchial wall and lumina. Conclusion. Since papillary bronchial squamous cell carcinoma of the hilum, which shows endobronchial exophytic growth, occasionally accompanies intraepithelial spreading at the front of invasive growth along the bronchial wall, intraoperative frozen section should be examined to determine the bronchial surgical margin.
