Applications of tissue microdissection in cancer genetics

A major obstacle to apply molecular biologic techniques effectively to the somatic genetic analysis of neoplastic tissue is the presence of abundant nonneoplastic elements in the analyzed specimen. These nonneoplastic elements, including reactive fibrous cells, vascular cells, and a variety of infiltrating white blood cells, may mask genetic alterations that otherwise would be easily detectable if the neoplastic cells were procured selectively. We have developed a microdissection technique which allows to selectively procure and genetically analyze small populations of neoplastic cells from the glass slide. In this report, we describe the microdissection technique and genetic analysis of archival frozen and paraffin-embedded tissue in general. Then, we review some implications of this approach of genetic analysis for mapping and cloning of new genes, identification of premalignant lesions, and differential analysis of different histologic components within the same tumor.