Epithelial ovarian carcinoma types and the coexistence of ovarian tumor conditions.

Objective. Ovarian carcinomas are presumed to arise within ovarian inclusion cysts or from a coexisting epithelial lesion in the ovary. Insight may be gained by relating different subtypes of ovarian cancer with the presence of coexisting tumor-like conditions. Methods. The Dutch nation-wide pathology database PALGA (Pathologisch Anatomisch Landelijk Geautomatiseerd Archief) identified the various histopathological subtypes of ovarian cancer in 824 patients diagnosed in 1996-2003, and recorded the presence of epithelial tumor conditions around the ovarian tumors. In addition, a PALGA database of all 153 consecutive patients referred to the Nijmegen University Medical Centre in 2007 for histopathological work-up was analyzed. Results. The prevalence of coexisting ovarian tumor conditions was 16.4% (135 out of 824 patients, (95% CI: 8.4%-24.4%)). The coexistence was highest for endometrioid, mucinous, clear cell, and borderline malignancies. The referral group revealed 35% (54 out of 153 patients, (95% CI: 28%-42%)) of coexisting epithelial ovarian tumor conditions. Conclusion. One in six patients with a malignant ovarian tumor has a coexisting epithelial tumor condition in the ovary, which is also rather frequently observed in the diagnostic work-up practice.