Cytomorphological spectrum in scar endometriosis: a study of eight cases

Objective: Endometriosis due to ectopic endometrial tissue that responds to hormonal stimulation and is extremely rare in a surgical scar appearing in 0.1% of women who have undergone Caesarean section. Fine needle aspiration cytology (FNAC) can be a valuable diagnostic aid in the evaluation of these subcutaneous abdominal masses. Methods: We present the cytomorphological spectrum in eight cases of abdominal wall endometriosis diagnosed by FNAC over a 6-year period (June 1998-June 2004) in Mubarak Al-Kabeer Hospital (Kuwait). The patients ranged from 27 to 56 years of age. Seven had a prior Caesarean section and one had a hysterectomy for fibroid. They presented 3-8 years later with nodules in/near the abdominal scar. Five cases presented with a painful nodule, fluctuant with the menstrual cycle. Results: Cytological findings comprised epithelial clusters and fusiform stromal cells with numerous haemosiderin-laden macrophages. Mild to moderate epithelial atypia was observed in three cases. A diagnosis of endometriosis was rendered in all the eight cases and tissue was available in four cases. Conclusions: Endometriotic nodules need to be differentiated from other benign/malignant masses and evaluated for possible malignant transformation. FNAC provides a safe and effective tool for diagnosis thereby obviating the need for other procedures.