A 25 year old female presents with a lower abdominal mass which shows a well-formed tooth on plain x-ray. The lesion is most likely to be which of the following?: (A) An immature teratoma, (B) A dysgerminoma, (C) An ovarian fibroma, (D) A mature cystic teratoma
Answer is D. Well-formed teeth are commonly seen in mature cystic teratoma and not in any of the other lesions.