Yolk sac tumor of the stomach with an adenocarcinomatous component: A case report with immunohistochemical analysis

Abstract

A 56-year-old male treated for a gastric yolk sac tumor with an adenocarcinomatous component is described. A mixed area of reticular and glandular neoplastic components was morphologically identified in this tumor. Immunohistochemically, the yolk sac tumor expressed alpha-fetoprotein (AFP), placental alkaline phosphatase (PLAP), and cytokeratin, but was negative for carcinoembryonic antigen (CEA). The adenocarcinoma was positive for CEA and cytokeratin, partially positive for PLAP, and negative for AFP. In the mixed area, the tumor cells were positive for cytokeratin, weakly expressed AFP and PLAP, and sporadically stained for CEA both in the reticular and glandular components. This area was identified as a transitional area of the yolk sac tumor and adenocarcinoma. These findings demonstrate that the yolk sac and adenocarcinomatous components are closely related. It also suggests that the tumor arose from multipotential neoplastic mucosal epithelial cells with both yolk sac and gastric mucosal phenotypes.

Germ cell tumor of the colon with an adenocarcinomatous component

“…In our case, the transitional zone between the adenocarcinoma and germ cell tumor was demonstrated histologically (with such cellular changes being referred to as tumor metaplasia and the process as opisthoplasia). [7][8][9]11,12,14,15 Therefore, the present case appears to be in accordance with a combination tumor. The results of IHC with p53 and CDX-2 also support this theory, because these two markers are usually positive in ordinary colon cancers.…”

“…According to this theory, the origin of germ cell neoplasms is considered to be primordial germ cells that may have been arrested along the migratory route from the hindgut yolk sac region into the embryonic genital ridge; this would account for many extragonadal germ cell neoplasms arising in the midline. [7][8][9]11,12,14,15 In a combination tumor, the various cell components may be derived from common stem cells. This phenomenon is so-called retrodifferentiation or dedifferentiation, but the process may be better described as blocked differentiation or mutation arrest in stem cells that is controlled by regulation of the genome.…”

“…Only a few reports have shown the colon and rectum as primary sites for YST, whereas several reports have documented YST as arising in the stomach. [8][9][10][11][12] On the other hand, germ cell tumors with choriocarcinoma as a component very rarely appear in the gastrointestinal tract, where choriocarcinoma usually adenocarcinomatous component and a pattern typical of germ cell tumor.…”

Gastric Yolk Sac Tumor Complicated with Beta-Human Chorionic Gonadotropin-Producing Metastases

“…The opposite results were observed with βhCG staining, which was positive in the liver, lung and omentum and negative in the stomach tumor and lymph nodes ( Table 2). (12 (4,7,8), choriocarcinomas (3) and embryonal carcinoma (4) although the relationship between the yolk sac and the other components is unclear. Some authors have proposed that these tumors could result from "retrodifferentiation" occurring in the cells during carcinogenesis (3,4,8,13 …”

Perforating abomasal ulcer caused by yolk sac tumor in a Holstein calf

“…2,5,8 The occurrence of germ cell tumor is very rare in animals compared to human beings. There have been only 2 case reports in cattle: a 28-day-old male Japanese black calf 4 and a 55-day-old male crossbred (Holstein-Friesian/Japanese Black) calf.…”