Malignant extraovarian endometriosis: a review

Abstract

Aims: Malignant transformation in extra-ovarian endometriosis is a rare but known complication. This distinct pathological entity is reviewed with a specific focus on aetiology and treatment.

Methods: Studies were identified by searching the English language literature in the MEDLINE database and by an extensive review of bibliographies from articles found through that search.

Findings: Up to 1% of women with endometriosis will develop endometriosis-associated neoplasm. Almost a quarter of the reported cases of malignancy in endometriosis have involved extra-ovarian tissues. In many cases, hormonal factors may play a role in its pathogenesis. Estrogen monotherapy in obese patients significantly increase the risk of malignant extra-gonadal endometrial transformation. Genetic anomalies have also been reported such as loss of heterozygosity on chromosome 5q. For patients with disease confined to the site of origin, a 82-100% 5-year survival has been noted for endometrioid cell type; disseminated intraperitoneal disease, however, has a very poor associated prognosis, with a 0-12% 5-year survival overall.

Conclusions: Women with endometriosis-associated cancers most likely represent a different class of patients than traditional ovarian cancer patients and may require different therapeutic options.