Immunohistochemistry of choriocarcinoma: An aid in differential diagnosis and in elucidating pathogenesis
Journal
American Journal of Surgical Pathology
Journal Volume
31
Journal Issue
11
Pages
1726-1732
Date Issued
2007
Author(s)
Abstract
Choriocarcinoma is traditionally described as being composed of cytotrophoblast and syncytiotrophoblast. Microscopically, these 2 types of cells are intimately associated with each other, forming a characteristic biphasic plexiform pattern, however, the nature of these 2 types of trophoblastic cells is not well understood. In this study, we used immunohistochemistry for several trophoblastic markers to analyze the trophoblastic subpopulations in 36 gestational choriocarcinomas. Eighty-one specimens including placenta, complete mole, placental site nodule, epithelioid trophoblastic tumor, and placental site trophoblastic tumor were analyzed. The antibodies included Mel-CAM, HLA-G, MUC-4, and β-catenin. A semiquantitative assessment of positive cells and the cellular localization of these markers were recorded. We found diffuse strong membranous and cytoplasmic staining for MUC-4 in mononucleate cells in all 36 cases (100%) and a similar pattern of localization in 28 cases (78%) for HLA-G. This distribution was similar to that in normal placentas, where MUC-4 and HLA-G are expressed in the trophoblastic cells of the trophoblastic columns and implantation site. In choriocarcinoma, mononucleate trophoblastic cells showed moderate immunoreactivity for Mel-CAM, a specific marker for implantation site intermediate trophoblast, in 78% of the cases. The MUC-4, HLA-G, and Mel-CAM-positive trophoblastic cells were larger than cytotrophoblastic cells, with more abundant cytoplasm, consistent with the morphology of intermediate trophoblast. In contrast, 31% of the choriocarcinomas contained a very small proportion (<5%) of mononucleate trophoblastic cells compatible with cytotrophoblast that was positive for nuclear β-catenin, a cytotrophoblast-associated marker. These results suggest that choriocarcinoma is composed predominantly of a mixture of syncytiotrophoblast and intermediate trophoblast with only a small proportion of cytotrophoblast. The presence of nuclear β-catenin staining in the cytotrophoblast of choriocarcinoma is consistent with the view that choriocarcinoma develops from transformed cytotrophoblastic cells which are presumably the cancer stem cells that differentiate into either intermediate trophoblast or syncytiotrophoblast. ? 2007 Lippincott Williams & Wilkins, Inc.
Subjects
β-catenin; Choriocarcinoma; HLA-G; Mel-CAM; MUC4
SDGs
Other Subjects
beta catenin; CD146 antigen; HLA G antigen; mucin 4; article; cancer stem cell; cell differentiation; cell structure; cell transformation; cellular distribution; choriocarcinoma; clinical article; controlled study; cytoplasm; cytotrophoblast; differential diagnosis; disease marker; epithelioid cell; female; human; human cell; human tissue; hydatidiform mole; immunohistochemistry; immunoreactivity; mononuclear cell; pathogenesis; placenta; syncytiotrophoblast; trophoblast; trophoblastic tumor; Antigens, CD146; beta Catenin; Cell Differentiation; Cell Nucleus; Cell Size; Choriocarcinoma; Diagnosis, Differential; Female; Histocompatibility Antigens Class I; HLA Antigens; Humans; Immunohistochemistry; Maryland; Mucins; Pregnancy; Taiwan; Trophoblastic Tumor, Placental Site; Trophoblasts; Tumor Markers, Biological; Uterine Neoplasms
Type
journal article