Giant cell carcinoma of the lung: comparative studies of the same cancer cells by light microscopy and scanning electron microscopy.

Surface ultrastructures of giant cell carcinoma cells were studied utilizing a technique developed by the authors which permits observation of the same cells by both light and scanning electron microscopy. Although some general similarity was shown to exist between giant cell carcinoma and squamous cell carcinoma cells, the following distinguishing features of giant cell carcinoma cells were demonstrated: (1) absence of keratinization, (2) full, bulging cellular edges and (3) presence of deep invaginations or small hollows. The features which distinguished giant cell carcinoma from adenocarcinoma cells were: (1) presence of many flattened cells, (2) folded cell surface, (3) absence of tight clusters of cancer cells and (4) few microvilli. Furthermore, the characteristic granularity observed in small cell carcinoma was not observed in giant cell carcinoma cells. Characteristically, cells of giant cell carcinoma are extremely large and flattened, engulf numerous leukocytes and have a bulging cellular edge.