Ultrastructural characterization of pulmonary neoplasms. I. The role of electron microscopy in characterization of the most common epithelial neoplasms.

We have attempted to summarize current concepts pertaining to the ultrastructural evaluation of epithelial pulmonary neoplasms, with an emphasis in potential clinicopathological correlations. Routine ultrastructural evaluation of the most commonly encountered pulmonary carcinomas seems to provide, in a significant number of cases, additional information that may be of help in patient management. Immunocytochemistry when employed as an adjunct to electron microscopic evaluation of pulmonary tumors also plays an important role in clarifying morphologic findings. With the advent of specific chemotherapy protocols and future development of monoclonal antibodies in the treatment of neoplasms, accurate tumor classification becomes crucial. The combined use of electron microscopy and immunocytochemistry seems to be extremely useful in providing accurate and reproducible criteria of great potential value in the overall assessment of pulmonary neoplasms. In part II of this study we will address the importance of the ultrastructural evaluation of less common epithelial and mesenchymal pulmonary neoplasms.