Structure and growth of tumors: the effect of Cartesian, cylindrical, and spherical geometries.

We present results of numerical simulations of a mathematical model simulating mass transfer in the development of a tumor, resulting in its encapsulation and lobulation. A modified generation term that reflects the population pressure on growth leads to nodular tumor growth. Simulations have been carried out in one dimensional Cartesian, cylindrical, and spherical geometries. Important differences between the three cases have been found. Simulation results in spherical geometry suggest the lobes near the center of the tumor to be larger than those near the capsule wall.