Spectrum of germ cell tumors: from head to toe.
Germ cell tumors (GCTs) occur most frequently in the gonads and are relatively rare in other sites, such as the pineal gland, neurohypophysis, mediastinum, and retroperitoneum. GCTs are thought to originate from primordial germ cells, which migrate to the primitive gonadal glands in the urogenital ridge. Extragonadal GCTs might also originate from these cells when the cells are sequestered during their migration. Pathologic subtypes of GCTs vary, and the prevalence of mixed tumors is high. These factors produce a diversity of radiologic findings and make prospective radiologic diagnosis difficult in many cases. However, similar radiologic findings have been observed in pathologically equivalent tumors in varying sites. Seminomas appear as uniformly solid, lobulated masses with fibrovascular septa that enhance intensely. Nonseminomatous GCTs appear as heterogeneous masses with areas of necrosis, hemorrhage, or cystic degeneration. Fat and calcifications are hallmarks of teratomas, most of which are benign. In immature teratomas, scattered fat and calcification within larger solid components are occasionally seen. These imaging characteristics reflect the pathologic features of each tumor, and histologically similar GCTs at varying sites have similar radiologic features. Knowledge of the pathologic appearances of GCTs and their corresponding radiologic appearances will allow radiologists to diagnose these tumors correctly.
Ueno
Teruko
T
Department of Radiology, Tsukuba University Hospital, 2-1-1 Amakubo, Tsukuba, Ibaraki 305-8576, Japan. u-teruko@mua.biglobe.ne.jp
Tanaka
Yumiko Oishi
YO
Nagata
Michio
M
Tsunoda
Hajime
H
Anno
Izumi
I
Ishikawa
Shigemi
S
Kawai
Koji
K
Itai
Yuji
Y
D000328:Adult; D002465:Cell Movement; D002648:Child; D002675:Child, Preschool; D005260:Female; D018237:Germinoma / Q000145:classification / Q000000981:diagnostic imaging / Q000196:embryology / Q000473:pathology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging / Q000196:embryology / Q000473:pathology; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000000981:diagnostic imaging / Q000196:embryology / Q000473:pathology; D010871:Pinealoma / Q000000981:diagnostic imaging / Q000196:embryology / Q000473:pathology; D011859:Radiography; D013736:Testicular Neoplasms / Q000000981:diagnostic imaging / Q000196:embryology / Q000473:pathology; D014463:Ultrasonography