CD10 is a marker for normal and neoplastic endometrial stromal cells

Immunohistochemical staining in the distinction between primary endometrial and endocervical adenocarcinomas: another viewpoint

Several studies have reported on the use of antibodies to monoclonal carcinoembryonic antigen (CEA) and vimentin (VIM) to distinguish between adenocarcinomas of endometrial (EM) and endocervical (EC) origin, with variably enthusiastic results. It is still unclear whether site of origin or pathway of differentiation (endometrioid [em] versus mucinous [m]) is more important in predicting immunohistochemical differences. In the present study, paraffin blocks from adenocarcinomas of known origin were retrieved and immunostained with monoclonal antibodies to VIM and CEA, as well as cytokeratins (CK) 4, 18, and 20, estrogen receptor (ER), and progesterone receptor (PR). Positivity was scored on a scale from 0 to 12, with emphasis on the pattern of differentiation (tumors with mixed patterns received separate scores for the em and m foci). Mean CEA scores for emEM (n = 27), mEM (17), mEC (10), and emEC (6) were 0.4, 0.9, 5.1, and 1.2, respectively. VIM scores were 6.9, 1.3, 0, 4.4; ER, 5.7, 4.2, 0, 1.6; PR, 7.6, 2.8, 0.1, 6.0; CK4, 9.2, 4.4, 8.5, 10.6; CK18, 6.4, 3.4, 5.5, 8.4; CK20, 0.7, 0, 0.5, 0.4. Both site and differentiation influenced these results, with the latter more important for VIM and PR, the former for ER, both for CEA (only mEC was frequently strongly positive), and neither for the CKs studied. No one stain or combination reliably distinguished endometrial from endocervical origin. The only immunostaining pattern that might identify a site of origin with more accuracy than hematoxylin & eosin evaluation alone is the combination of high VIM and ER scores in an endometrioid carcinoma, suggesting with about 95% accuracy in this series an endometrial origin of the tumor.

Recent advances in immunohistochemistry in gynaecological pathology

Recent years have witnessed significant developments in the use of immunohistochemistry in diagnostic gynaecological pathology. This review details the most significant of these. In ovarian pathology, differential cytokeratin staining (CK7 and 20) assists in distinguishing between a primary ovarian adenocarcinoma and a metastatic adenocarcinoma, especially of colorectal origin. The development of markers characteristic of ovarian sex cord-stromal tumours (especially alpha-inhibin) facilitates diagnosis of these neoplasms which is often difficult by morphology alone due to the wide differential diagnosis. In the uterus, the distinction between a primary endometrial and endocervical adenocarcinoma may be facilitated by use of a small panel of antibodies, including CEA, ER and vimentin. Newly developed antibodies such as CD10 and h-caldesmon may be of use in the diagnosis of uterine mesenchymal lesions, especially in the distinction between endometrial stromal and smooth muscle lesions. Proliferation markers, such as MIB1, are of value in the cervix in the diagnosis of preinvasive squamous and glandular lesions. Recent studies have shown that cervical adenoma malignum exhibits a gastric phenotype. Advances have also been made in trophoblastic disease with the development of antibodies reactive against trophoblast such as alpha-inhibin, mel-Cam and p57. A newly developed monoclonal antibody HMGIC which is expressed in vulvovaginal aggressive angiomyxoma may prove to be of value in the often difficult distinction of this lesion from its histological mimics.

An immunohistochemical analysis of endometrial stromal and smooth muscle tumors of the uterus: a study of 54 cases emphasizing the importance of using a panel because of overlap in immunoreactivity for individual antibodies

The expression of desmin, h-caldesmon, calponin, CD10, CD34, CD99, inhibin, and keratin (AE1/3-Cam 5.2) was studied in 10 conventional leiomyomas, 9 highly cellular leiomyomas, 9 epithelioid smooth muscle tumors, 9 leiomyosarcomas, 10 endometrial stromal tumors (4 with smooth muscle metaplasia), and 7 uterine tumors resembling ovarian sex cord tumors (UTROSCTs). c-kit expression was tested in 10 endometrial stromal tumors, 7 UTROSCTs, and 9 leiomyosarcomas. Desmin was positive in almost all smooth muscle tumors except those of epithelioid type, which were positive in only about half of the cases. It also stained areas of smooth muscle differentiation in endometrial stromal tumors and five of seven UTROSCTs. h-caldesmon was positive in almost all nonepithelioid smooth muscle tumors and in areas of smooth muscle differentiation in endometrial stromal tumors; it was positive in only about half of the epithelioid smooth muscle tumors and negative in all UTROSCTs. Calponin was positive in most tumor types. CD10 was positive in nine of 10 endometrial stromal tumors and five of seven UTROSCTs, although very focally in the latter group. It was also expressed, however, in almost all leiomyosarcomas, almost 50% of highly cellular leiomyomas, and rarely in the other smooth muscle tumors. CD34 was negative in the tested tumors with rare exceptions. CD99 and inhibin were positive in four of seven and one of seven UTROSCTs. Keratin positivity was found in most (five of seven) UTROSCTs and occasionally in smooth muscle tumors (seven of 37). c-kit was negative in all endometrial stromal tumors, UTROSCTs, and leiomyosarcomas. The major conclusions of this study are as follows: 1) Pure endometrial stromal tumors are usually desmin negative. 2) In contrast to some previous studies, CD10 expression was often seen in smooth muscle tumors, including most leiomyosarcomas and almost half of highly cellular leiomyomas. As a result, a panel of CD10, h-caldesmon, and desmin should be used and will distinguish endometrial stromal tumors from highly cellular leiomyomas in most cases. 3) In contrast to a previous study, no significant differences in immunoreactivity were seen between h-caldesmon and desmin in tumors with smooth muscle differentiation. 4) The absence of h-caldesmon in UTROSCTs helps separate them from epithelioid smooth muscle tumors. 5) UTROSCTs may express epithelial, stromal, and smooth muscle markers, suggesting divergent differentiation. 6) Our study shows less frequent inhibin expression in the sex cord-like elements of the UTROSCTs than in other studies. 7) c-kit may help distinguish metastatic endometrial stromal tumors of the uterus (c-kit negative) from gastrointestinal stromal tumors (c-kit positive). 8) CD34, CD99, and keratin have no or minimal role in this area, but keratin positivity in smooth muscle tumors should not lead to their confusion with epithelial tumors.