Endometriosis found in Caesarean section incision scars is unusual but happens in less than 1% of cases. Endo can grow in almost all areas of the body and travels there by direct extension, by the bloodstream by the lymphatic system and by direct implantation into surgical incisions and hernias.
“A study of 30 women who had abdominal wall endometriomas (AWE) surgically removed after Caesarean section found that the main symptom for detection and surgery two-thirds of the time was cyclical pain, while 13.3% of patients had no symptoms.
On average, the time that passed between the previous cesarean section and the onset of symptoms was 55.2 months and the mean size of the excised mass was 42 mm. So, it was very slow-growing, which is to be expected. The risk increased with each additional surgery.
The researchers advocate the creation of gene expression profiles for endometriosis and the histological evaluation of endometriotic fibrosis. They also recommend the evaluation of surgical margins for AWE in a larger number of cases to minimize the risk of it growing back.
Basically, if a nodule is found near or in a C-section scar, even years after the surgery, endo should be considered as one of the possible reasons. Microscopic implantation can grow very slowly and end up feeling like a mass in the area. The treatment is removal by an expert surgeon in order to avoid it from growing back. This expert may be a gynecologic oncologist who can evaluate for other reasons for this mass and also remove it in a way that minimizes recurrence.
Hasan A., Deyab A., Monazea K. et al. Clinicopathological evaluation of surgically removed abdominal wall endometriomas after caesarean section. Ann Med Surg. 2021 Jan 21; 62: 219- 224; doi: 10.1016 / j.amsu.2021.01.029