Hydrocele of the canal of Nuck - Rare differential for vulval swelling.

Patent canal of Nuck is one of the rare developmental entities in females, presenting clinically as an inguino-labial swelling. The usual content of this sac is fluid being secreted by the peritoneal mesothelium. In rare cases, ovary alone or with fallopian tube may prolapsed out into the sac. We report the rationale use of diagnostic algorithm in a case of ovarian hernia into the patent canal of Nuck, to differentiate it from more common clinical mimics. Furthermore, in the present case, a knowledge of the entity and targeted scrutiny, led to a correct identification of the prolapsed ovary, preventing an unwarranted oophorectomy in the garb of neoplasia.