The metastatic spread of myeloma and leukemias in men.

This investigation was based on the analysis of 580 autopsy records of patients with plasma cell myeloma or any type of leukemia. The data were collected by the Department of Pathology at Roswell Park Memorial Institute between 1956 and 1965. The primary purpose of this paper was to elucidate the metastatic process in myelomas and different types of leukemia. Two mutually exclusive hypotheses were tested, i.e. whether the spread of a cancer from the primary tumor throughout the body was due to a simple diffusion or if a cascade process took place. The basic definition of the "cascade or multistep" diffusion of cancer is that it takes place in steps; that is, at least one intermediate step is usually required for the disease to progress from the primary tumor to generalized dissemination throughout the body. It appeared that either the liver or spleen are the two major diffusing sites; that is, no generalized metastasis occurs unless the spleen and/or liver are seeded first.