Endometrioid adenocarcinoma in an extrauterine adenomyoma.

Background: Focal involvement by endometrioid adenocarcinoma in an extrauterine adenomyoma in a patient with stage 1 endometrioid adenocarcinoma presented a unique problem in staging and management of extrauterine endometrial cancer.

Case: A 49-year-old white woman, gravida 0, referred for endometrioid adenocarcinoma was found to have an extrauterine adenomyoma involved with endometrioid adenocarcinoma in the inguinal canal after surgical staging. The endometrioid adenocarcinoma involving the extrauterine adenomyoma was low-grade and noninvasive, representing an embryological anomaly transformed into endometrioid adenocarcinoma by unopposed estrogen. Stage 1A, grade 2 endometrioid adenocarcinoma was diagnosed and observed.

Conclusion: Stage 1 endometrioid adenocarcinoma with concurrent, noninvasive, focal involvement in an extrauterine adenomyoma represents a secondary site and does not alter disease stage.