Introduction: Dermoid cysts are rarely located in extraovarian sites, representing an extremely uncommon lesion of the round ligament. The differential diagnosis of an inguinal lesion that proved to be a dermoid cyst deriving from the round ligament is presented with a review of the literature.
Case report: A case of a 27-year-old female with a dermoid cyst arising from the round ligament and lying inside the inguinal canal, which was tender and palpable, is reported.
Discussion: Underlining their origin, clinical manifestation, gross appearance and pathology, we differentiate dermoid cysts mainly from epidermoid cysts and mature cystic teratomas, analyzing the importance of such a distinction to the possibility of malignant degeneration and recurrence of a dermoid cyst in the round ligament.