abstract
One of the most remarkable of human
neoplasms,
the yolk sac tumor, is reviewed, emphasizing its histologic diversity
and differential diagnosis, occurrence at many sites, and the shared
passion for this unique neoplasm of Dr Gunnar Teilum (who deserves
almost all credit for delineation of the nature of the tumor and its
features) and Dr Aleksander Talerman (who made his own contribution to
our knowledge of it) and the friendship it helped forge between these 2
distinguished
pathologists. In a unique series of articles, beginning in
the early 1940s, Teilum delineated the distinctive features of the
neoplasm and recognized that it was 1 of 2 initially included as
"mesonephroma ovarii" by Dr Walter Schiller in 1939 (
the second we now
know as clear cell carcinoma). Teilum named the tumor "endodermal sinus
tumor" because it came to his attention that papillary formations common
in the yolk sac tumor resembled the endodermal sinuses of the rat
placenta. He focused on the histogenesis of the tumor and its
morphologic features culminating in a classic paper in
Cancer
in 1959. Although Teilum and others recognized that yolk sac tumor
could be a component of mixed germ cell tumors, Talerman was one of the
first to emphasize that, particularly in the
testis, it was common to
see yolk sac tumor as a component of a mixed germ cell tumor. Teilum,
working in Copenhagen, and Talerman, when the former was alive, working
in Rotterdam, developed a warm friendship in part due to their great
interest in the yolk sac tumor, although it also extended to other areas
of gonadal neoplasia and indeed beyond the boundaries of medicine when
they shared time together. The typical histologic features of the yolk
sac tumor are the reticular-microcystic patterns Teilum described, but
various other patterns, including solid and even rarer ones such as
glandular and hepatoid, are now well known. There are some interesting
variations in the age distribution of this tumor at various sites: for
example, vaginal examples are almost restricted to children under 2
years of age; those of the testis that are pure also occur mostly in
young boys (average age about 20 months) but are occasionally seen in
later years;
ovarian
examples peak at about 19 years of age; mediastinal forms are mostly
restricted to young adult males. Brief consideration is also given to
the occurrence of this tumor at well-known extragonadal sites such as
retroperitoneum, mediastinum, and pineal as well as more exotic
locations. Note is made of the r
ecently emphasized occurrence of the
yolk sac tumor on the background of a somatic neoplasm, most often
endometrioid carcinoma of the ovary. Given the wide ranging and
fascinating clinical and pathologic aspects of the neoplasm, it is no
surprise that it continues to be a source of great interest to any
pathologist who sees one or more examples, and we are indebted to Dr
Teilum for his monumental studies and to Dr Talerman for his own
contributions.