THE BIOLOGY OF TERATOMAS
3
tomas are made up of recognizable somatic tissues corresponding to
either fetal or adult stages of development.
Willis (1935) expressed the opinion that no sharp distinction can be
made between the embryonal and adult tumors, and the term teratocarcinoma (Melicow, 1955) is commonly used for tumors containing
both embryonal and adult elements. Choriocarcinoma is a highly malignant tumor composed of cytotrophoblast and syncytial trophoblast.
Friedman (1959) stated that no sharp dividing line can be drawn between the morphologically classic choriocarcinoma and many embryonal
carcinomas, and it is generally agreed that embryonal carcinoma is the
precursor of both the trophoblastic and the teratoid tumors. Melicow
(1955) discussed the relationships between germinal tumors of the human
testis and concluded that the three tumors designated embryonal carcinoma, teratocarcinoma, and adult teratoma, might represent consecutive
stages in the development of a single kind of neoplasm. Teratocarcinoma
might be considered a partially differentiated embryonal carcinoma, and
might be regarded as an intermediate stage between embryonal carcinoma and adult teratoma. Friedman (1959) and Friedman and Moore
(1946) also believed that adult teratomas represent matured tetratocarcinoma. Midgley and Pierce (1961) presented evidence to support the
contention that human embryonal carcinoma may be a stage in the development of choriocarcinoma. These points of view receive support from
our observations on the development of spontaneous teratomas of strain
129 mice (Stevens, 1959). The tumors in fetal and infant mice are
composed of undifferentiated embryonal-type cells (embryonal carcinoma) . At 5 days and older, the tumors contain both differentiated and
embryonal elements (teratocarcinoma), and in most adults the tumors
are completely differentiated and lack embryonal elements (teratoma).
There is a remarkably high frequency of coincident seminoma and
teratoma in man (Halley, 1963). Of 43 germ cell tumors, 19 consisted of
seminomas alone, 11 consisted of teratoma (embryonal carcinoma, chorionic carcinoma, teratocarcinoma), and 13 consisted of seminoma and
teratoma. Halley considered seminoma and teratoma as separate and
dissimilar tumors. Cabanne (1957) and others have noted that teratoid
tumors (dysembryomas) frequently are associated with seminoma in the
same testis.
III. Distribution
A. Species
Detailed descriptions of the composition of teratomas in human beings
have been published by Willis (1948, 1952, 1958), Dixon and Moore
(1952), Friedman and Moore (1946), Masson (1956), Nicholson (1929,
3
tomas are made up of recognizable somatic tissues corresponding to
either fetal or adult stages of development.
Willis (1935) expressed the opinion that no sharp distinction can be
made between the embryonal and adult tumors, and the term teratocarcinoma (Melicow, 1955) is commonly used for tumors containing
both embryonal and adult elements. Choriocarcinoma is a highly malignant tumor composed of cytotrophoblast and syncytial trophoblast.
Friedman (1959) stated that no sharp dividing line can be drawn between the morphologically classic choriocarcinoma and many embryonal
carcinomas, and it is generally agreed that embryonal carcinoma is the
precursor of both the trophoblastic and the teratoid tumors. Melicow
(1955) discussed the relationships between germinal tumors of the human
testis and concluded that the three tumors designated embryonal carcinoma, teratocarcinoma, and adult teratoma, might represent consecutive
stages in the development of a single kind of neoplasm. Teratocarcinoma
might be considered a partially differentiated embryonal carcinoma, and
might be regarded as an intermediate stage between embryonal carcinoma and adult teratoma. Friedman (1959) and Friedman and Moore
(1946) also believed that adult teratomas represent matured tetratocarcinoma. Midgley and Pierce (1961) presented evidence to support the
contention that human embryonal carcinoma may be a stage in the development of choriocarcinoma. These points of view receive support from
our observations on the development of spontaneous teratomas of strain
129 mice (Stevens, 1959). The tumors in fetal and infant mice are
composed of undifferentiated embryonal-type cells (embryonal carcinoma) . At 5 days and older, the tumors contain both differentiated and
embryonal elements (teratocarcinoma), and in most adults the tumors
are completely differentiated and lack embryonal elements (teratoma).
There is a remarkably high frequency of coincident seminoma and
teratoma in man (Halley, 1963). Of 43 germ cell tumors, 19 consisted of
seminomas alone, 11 consisted of teratoma (embryonal carcinoma, chorionic carcinoma, teratocarcinoma), and 13 consisted of seminoma and
teratoma. Halley considered seminoma and teratoma as separate and
dissimilar tumors. Cabanne (1957) and others have noted that teratoid
tumors (dysembryomas) frequently are associated with seminoma in the
same testis.
III. Distribution
A. Species
Detailed descriptions of the composition of teratomas in human beings
have been published by Willis (1948, 1952, 1958), Dixon and Moore
(1952), Friedman and Moore (1946), Masson (1956), Nicholson (1929,