A case of primary mesenteric embryonal carcinoma

We describe a case of primary mesenteric embryonal carcinoma. The patient was a 73-year-old man who presented with a huge mass palpable at the right upper side of the abdomen. Laboratory evaluations showed very high alpha-fetoprotein and PIVKA-II levels, and an abdominal computed tomographic scan demonstrated a mass contiguous with the liver. These findings suggested hepatic cell carcinoma extending beyond the liver. However, angiography showed the mass to be supplied mainly by the middle colic artery and greater omentum artery, suggesting a mesenteric tumor. Gastroscopy demonstrated a IIc lesion in the anterior wall of the antrum. This lesion was histologically diagnosed to be moderately differentiated adenocarcinoma. The large tumor adjacent to the liver was diagnosed to be a primary mesenteric tumor or a metastatic mesenteric tumor from arising gastric cancer. At laparotomy, a huge tumor was found in the gastrocolic ligament. The tumor adhered to the distal part of stomach, the transverse colon, and the gallbladder. En-bloc resection of the tumor was performed, including the distal part of stomach, Part of the transverse colon, and the gall-bladder. The tumor mass measured 26.0 x 21.0 x 9.0 cm, weighted 2750 g, and showed central necrosis and hemorrhage. The histopathological diagnosis was a primary embryonal carcinoma originating in the mesentery. Primary mesenteric embryonal carcinoma is extremely rare. To our knowledge, no other cases have been reported. We describe this case and briefly discuss the related literature.