This is a case report of radiologically occult in situ squamous cancer of the right-sided pulmonary hilus, which had been detected. among 2, 377 persons by mass sputum cytology as a lung cancer detection program of Tochigi Cancer Detection Center.
As a first clue for the detection, dyskaryotic squamous cells were firstly found in the sputum of a 68-years-old patient. Thrice re-examination of the sputum revealed various kinds of keratotic atypical cells, suggesting a squamous cell carcinoma. Stenosis of B-6-a was disclosed by a bronchoscopic exmination. By detailed histologic exmination of the bronchial tree in resected specimens, it was found squamous cell carcinoma confined to the bronchial epithelial layer of B-6-a, with about half rice-corn sized elevation and extending into the epitheliums of B6-a-i & ii in small parts. As a total, this in situ cancer was less than several millimeter in diameter.
