RESUMO
@#Malignant transformation of a mature cystic teratoma (MCT) or dermoid cyst in the ovary occurs only 1 to 2% of cases of MCTs. Only 6 cases of small cell carcinoma arising from a MCT have been reported. The patient is a 36 year-old G2P2(2002) who presented with an enlarging abdominal mass and right lower quadrant pain. She was diagnosed with a dermoid cyst four years prior to admission, but no surgical intervention was done. On admission, ultrasound revealed multiple pelvo-abdominal masses consistent with dermoid cysts. The patient underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy, peritoneal fluid cytology, bilateral pelvic lymph node dissection, excision of enlarged paraaortic lymph nodes and infracolic omentectomy. Histopathology revealed a small cell carcinoma arising from a MCT in the left ovary consistent with a Stage IIIA1ii tumor. She underwent chemotherapy with 4 cycles of Etoposide-Cisplatin and has no evidence of disease 3 months after treatment.