[Differential diagnosis among reactive mesothelia, adenocarcinoma and malignant mesothelioma]

We tried to distinguish reactive mesothelia (RM), adenocarcinoma (AC), and malignant mesothelioma (MM) in the body fluid. Morphometrically, nuclear uneveness index (NUI) of the benign and neoplastic mesothelial cells was smaller than that of the adenocarcinoma cells. About N/C area ratio, that of reactive mesothelial cells was larger than that of two types of malignant cells (lung AC and MM). But that of gastric AC was the largest in all groups. Ultrastructurally, length to diameter ratio (LDR) of mesothelioma cells was statistically greater, and intermediate filaments of benign and malignant mesothelial cells were more abundant than that of AC. For immunohistochemical diagnosis, it was necessary to use appropriately the specific and sensitive markers for benign and malignant mesothelial cells, or AC cells in combination.