Morphological Characteristics and Prognosis of the Small Size of Peripheral Squamous Cell Carcinoma of the Lung

Nineteen cases of surgically resected small size of squamous cell carcinoma of less than 3.0 cm. in diameter arising from the periphery of the lung were studied morphologically and prognostically. Some of them were difficult to differentiate both grossly and radiologically from peripheral adenocarcinomas, possessing pleural indentation and fibrotic foci in the center of the tumor as in adenocarcinoma. None of the cases extended through the elastic layer of the pleura, 16 out of 19 cases were free of lymph node metastases, and thus the prognosis was good in the majority of the patients. Prognostic significance of collagenization and hyalinization within tumor mass was not obvious in our cases of peripheral squamous cell carcinoma of the lung.