Endometriosis is the presence of endometrial glands and stroma at extrauterine sites. These ectopic endometrial implants are known as endometrioma  when they present in form of a discrete lump. Endometriosis involving the abdominal wall is an unusual phenomenon which should be considered in the differential diagnosis of abdominal wall masses in women.

This case report is about a twenty six years old lady ,para three, abortion two, who presented to gynaecology outpatient department with complaints of continuous pain abdomen since eight months on the  right side of the  midline infraumbilical scar.Abdominal  examination revealed a tender small lump around 4x3 cm in the infraumbilical region about 1.5–2 cm lateral to the midline.She gave a history of only tubal ligation and like us she too was unaware of her hysterotomy scar which accidentally came to our notice during laparotomy.The initial ultrasound gave a normal report. A repeat scan detected the mass with a differential diagnosis of desmoid tumor and nodular fascitis.FNAC strongly suspected endometriosis. Surgical resection with disease free margin was done. Histopathology confirmed ectopic endometrium.

 To diagnose endometriosis one has to have a strong suspicion in mind especially when the picture is not classic like in our case, with no relation to menses. Tissue handling should be kept to minimum in any gynaecological and obstetric surgeries to prevent such non serious but annoying post operative complication.