IMMUNOPHENOTYPIC FEATURES OF UTERINE STROMAL CELLS - CD34 EXPRESSION IN ENDOCERVICAL STROMA

CD34 is a myeloid progenitor cell antigen present in endothelial cells and some other mesenchymal cells, including perivascular and periadne xal dermal fibroblasts. It was evaluated immunohistochemically in uter ine stromal tissue and in 4 aggressive angiomyxomas and 6 endometrial stromal sarcomas with potentially related and similar stromal tissues. The stromal cells in normal endocervix and endocervical polyps were s trong ly CD34 positive irrespective of the cycle phase, and negative f or muscle actins. Ectocervical stroma was variably ably but generally less CD34 reactive. In the endometrium, the CD34 reactivity was limite d to the stromal cells of the basal endometrium and was found only in 4 of 20 from proliferative endometria and 1 of 8 from secretory endome tria. The uterine cervical and myometrial smooth muscle tissues showed CD34 positive cells only between the muscle bundles and around the ve ssels. In pelvic aggressive angiomyxomas and endometrial stromal sarco mas the tumour cells were CD34 negative and only the vascular endothel ial cells were positive. Endothelial cell-specific antigen, CD31, was identified only in endothelial cells and was not present in the endoce rvical stroma. These results illustrate the particular immunohistochem ical profile of endocervical stromal tissue, namely the strong CD34 ex pression. The CD34 reactivity of the endocervical tissues should be no ted and not confused with neoplasms known to be strongly CD34 positive , such as angiosarcomas, Kaposi's sarcomas and some other spindle cell sarcomas.