Ovarian mucinous cystic tumor of borderline malignancy with a mural nodule of anaplastic spindle cell carcinoma: a case report

Ovarian cystic tumors with a mural nodule are a rare entity. We report a case of a mural nodule of anaplastic spindle cell carcinoma in an ovarian mucinous cystic tumor of borderline malignancy. The patient was a 45-years-old Japanese woman who presented with an ovarian cyst. She suffered from mature cystic teratoma of both ovaries 9 years before the present history. Image analysis and laboratory data showing a high serum CA19-9 level suggested ovarian malignancy. She underwent bilateral salpingo-oophorectomy with hysterectomy and omentectomy. There was a mural nodule in the ovarian mucinous cystic lesion. Microscopically, the nodule was composed of spindle-shaped cells with severe nuclear atypia. Immunohistochemical analysis allowed the cells to be categorized as anaplastic spindle cell carcinoma. Fifteen months after the operation the patient is alive without any clinical findings of tumor recurrence. To the best of our knowledge in the English literature, this is the first report of a mural nodule of an anaplastic spindle cell carcinoma within an ovarian mucinous cystic borderline tumor harboring previously confirmed cystic teratoma.