Squamous cell carcinoma , serous adenocarcinoma and osteosarcoma arising in a mature cystic teratoma of the ovary: a case report and literature review

Background: Malignant transformation of mature ovarian teratomas is a rare phenomenon, occurring mainly in postmenopausal women. Secondary malignancies may originate in either of the ectodermal, mesodermal and endodermal germ layers. Sarcomatous transformation is much less common than transformation into a malignant epithelial component. Cases of smooth muscle sarcoma, angiosarcoma, osteosarcoma, malignant fibrous histiocytoma, rhabdomyosarcoma, and chondrosarcoma arising in mature ovarian teratomas have been described in the literature so far. Case presentation We report a case of squamous cell carcinoma, serous adenocarcinoma and osteosarcoma presenting in a mature ovarian teratoma in a 55-year-old woman. The presence of a mixture of the three tumour components in a background of typical dermatomal cysts, where the transition from normal squamous epithelium to squamous cell carcinoma was seen, is strong evidence that this particular tumour combination originated from an ovarian teratoma. Conclusions: We report a rare tumour combination occurring in an ovarian teratoma and to date, to our knowledge, such a tumour combination should be described for the first time. More similar cases are needed to elucidate the biological pathways and underlying molecular mechanisms of these rare tumour combinations.