Rhabdomyosarcoma and chondrosarcoma arising in a mature cystic teratoma of the ovary and osteosarcoma arising in its recurrence

A case of malignant transformation within a mature cystic teratoma (MCT) including two different sarcoma types (rhabdomyosarcoma and chondrosarcoma) in the initial tumor and a third new type (osteosarcoma) in the second recurrence 16 months later in a 64-year-old postmenopausal woman is presented. To our knowledge, this is the only second case with multiple sarcomas developed within an MCT since 1954. Also this is the first case that shows synchronous rhabdomyosarcomatous and chondrosarcomatous transformation within the MCT at the time of primary surgery and osteosarcomatous differentiation in the recurrence.