CD34⁺ fibrocytes in normal cervical stroma, cervical intraepithelial neoplasia III, and invasive squamous cell carcinoma of the cervix uteri

Abstract.

CD34⁺ fibrocytes are widely distributed in normal connective tissues but have been reported to be absent within the stroma associated with invasive carcinomas. In the present study we investigated the presence and distribution of CD34⁺ fibrocytes and α-smooth muscle actin (α-SMA) positive myofibroblasts in cervical intraepithelial neoplasia III (CIN III; n=8), invasive carcinoma of the cervix (n=18) and adjacent normal cervical stroma. Normal cervical stroma and the stroma adjacent to CIN III disclosed a dense network of CD34⁺ fibrocytes, whereas the stroma of invasive carcinoma was virtually free of this cell population. Early stromal invasion by squamous carcinoma was characterized by a focal loss of CD34⁺ fibrocytes. α-SMA-positive myofibroblasts were not seen in the normal cervical stroma but occurred in six of eight cases of CIN III adjacent to the atypical epithelium. The stroma of invasive carcinoma was made up of large amounts of haphazardly arranged α-SMA-positive myofibroblasts. In the setting of the present study, a loss of CD34⁺ fibrocytes was specific for stromal alterations associated with invasive carcinoma and proved to be a sensitive tool in detecting small foci of stromal invasion. Therefore, detection of a loss of CD34⁺ fibrocytes may constitute an adjunctive tool in detecting (1) early stromal invasion and (2) invasive carcinoma in small biopsy specimens. Moreover, the present study shows that CD34⁺ fibrocytes and myofibroblasts play an important role in stromal remodeling associated with invasive squamous cell carcinoma of the cervix.