Background: The development of a mass in a surgical scar poses a diagnostic dilemma due to similarities in appearance to hernias, abscesses, hematomas or desmoid tumors. Scar endometriosis is uncommon and malignant change within this ectopic tissue is rare.
Case report: The case of a 55-year-old woman with an isolated clear cell adenocarcinoma in an area of scar endometriosis more than 17 years after a cesarean section is presented. Initially, this tumor was thought to be a chronic abscess, but was finally diagnosed as clear cell carcinoma. This case highlights the difficulties in preoperative diagnosis as well as the poor prognosis of these tumors.
Conclusion: Accurate diagnosis of a lump within a scar is important to define the prognosis and treatment. Further data are needed for the management of this pathology.