Ectopic Pregnancy Developing in a Cyst of the Canal of Nuck

BACKGROUND: A cyst of the canal of Nuck is a rare cause of inguinal swelling in adult women. Ectopic pregnancies that implant to rare regions are sometimes challenging to diagnose. CASE: A 45-year-old woman presented with painful swelling in her right groin with a positive urine pregnancy test. Ultrasonography, magnetic resonance imaging, and the histopathologic result of dilation and curettage suggested ectopic pregnancy in the right inguinal canal. Exploratory laparotomy, extraction of the right inguinal mass lesion, and closure of the deep inguinal ring were performed. The mass lesion measured 433 cm, and the histopathologic finding revealed an unusual ectopic pregnancy in the cyst of the canal of Nuck. CONCLUSION: In women of reproductive age presenting with painful swelling of the groin, ectopic pregnancy in a cyst of the canal of Nuck should be ruled out.