title: Rhabdoid colorectal carcinomas: reports of two cases.
abstract: Rhabdoid colorectal carcinomas are very rare and only 10 cases have been previously reported. We report two cases of rhabdoid colorectal carcinoma, one arising in the sigmoid colon of a 62-year-old man and another in the rectum of an 83-year-old woman. In both cases, the patients had advanced tumors with lymph node metastases. The tumors mostly showed a diffuse arrangement with rhabdoid features and small glandular regions were combined. Transitional areas from the adenocarcinomas to the rhabdoid tumors were also noted. Adenocarcinoma cells were positive for mixed cytokeratin (CK), CK20 and epithelial membranous antigen (EMA), but focal positive for vimentin. The rhabdoid tumor cells were positive for mixed CK, but focal positive or negative for CK20 and EMA. In addition, they were diffusely positive for vimentin, but negative for desmin. The histological and immunohistologial findings of these two cases suggest that the rhabodid tumor cells originated from dedifferentiated adenocarcinomas.
authors.affiliation: Department of Pathology, Research Center, Aerospace Medical Center, Republic of Korea Air Force, Cheongju, Korea.
authors.forename: Sang Hwa
authors.initials: SH
authors.lastname: Lee
authors.forename: Hyesil
authors.initials: H
authors.lastname: Seol
authors.forename: Wook Youn
authors.initials: WY
authors.lastname: Kim
authors.forename: So Dug
authors.initials: SD
authors.lastname: Lim
authors.forename: Wan Seop
authors.initials: WS
authors.lastname: Kim
authors.forename: Tae Sook
authors.initials: TS
authors.lastname: Hwang
authors.forename: Hye Seung
authors.initials: HS
authors.lastname: Han
keywords: Adenocarcinoma; Colon; Rectum; Rhabdoid tumor