A Rare Case of Primary Apocrine Adenocarcinoma Arising Within a Mature Cystic Teratoma of the Ovary, Metastatic to a Supraclavicular Lymph Node

: Mature cystic teratoma of the ovary is one of the most common benign tumours among reproductive aged women. Malignant transformation of a mature cystic teratoma is uncommon and metastatic malignancy is extremely rare. We report the first known case of an apocrine adenocarcinoma arising within an ovarian mature cystic teratoma which on follow-up six months later was found to be metastatic to the left supraclavicular lymph node. There are usually no pre-operative findings to raise the suspicion of malignancy in an ovarian teratoma, so awareness by the pathologist is therefore paramount.