Minimal neoplasia may be defined as a small cancer that has progressed beyond its site of primary origin into the surrounding tissue, but that has not yet reached the stage of deeper invasion or metastasization. The basic principles of this minimal cancer are presented in chapters on molecular, biological and experimental aspects, and, in particular, on the clinical manifestations in various organs: preleukemia, incipient lymphoma, and minimal carcinomas of the uterine cervix, breast, thyroid, larynx, lung, prostate, stomach and colon. A separate chapter is devoted to cryptic gliomas. The latest morphological methods including cytology, early clinical diagnostics and, in particular, radiodiagnostics, are considered. The reader can expect up-to-date information about prompt diagnosis of the very early manifestations of cancer, together with inferences on therapy, which, especially in tumors of the uterine cervix, breast and thyroid, differs considerably from the treatment of advanced neoplasia.