Malignant degeneration of mature cystic teratoma of the ovary with small bowel metastasis incidental serous cystadenoma collision tumor of the right ovary.

Mature Cystic Ovarian Teratoma (MCOTs) are the most common benign ovarian neoplasms, representing around 20% of all ovarian neoplasms with middle age women representing the majority of patients. They usually include two germ cell layers being well differentiated and rarely they demonstrate malignant transformation with squamous cell carcinoma being the most common malignant transformation. In our case, we report an interesting case of a 45 years old lady who was unfortunate to have a MCOT with malignant degeneration and distant metastasis. We concluded that MCOT malignant degeneration is rare, however, if not caught early, mortality can be high. MCOT, Ovary, Small Bowel, Teratoma, Collision tumor.