ABSTRACT
Fetal tumors are rare congenital anomalies that can be located in different parts of the fetal body. As in adults, tumors in the fetus may arise from any tissue as a consequence of developmental errors during embryogenesis. The ‘cell rest’ theory has been suggested as a possible explanation of fetal tumor development: according to this theory, more cells are produced than are required for the formation of an organ or tissue, and fetal tumors are the results of developmental errors in these surplus embryonic rudiments. A genetic mechanism has also been suggested as a possible factor in the complex patho-genesis of certain embryonic tumors. 1
