%0 Journal Article %T Primary Malignant Mixed M¨¹llerian Mesodermal Tumor Mimicking a Rectosigmoid Carcinoma: A Case Report and Review of the Literature %A Sakshi Kapur %A Levin Miles %J Case Reports in Oncological Medicine %D 2014 %I Hindawi Publishing Corporation %R 10.1155/2014/948908 %X We report a case of a 53-year-old female who presented with chronic constipation and abdominal discomfort for six months. Her past surgical history was significant for a total abdominal hysterectomy with bilateral salpingooophorectomy, performed eight years ago, for uterine fibroids and endometriosis. Workup revealed a mass measuring 5 ¡Á 4.5 ¡Á 2£¿cm in the rectosigmoid colon. Patient underwent a low anterior resection and a fungating, centrally ulcerated rectosigmoid mass with a positive mesorectal margin was removed. Histopathology revealed a heterologous mixed mesodermal tumor (chondroid and osteoid elements). The epithelial component was compatible with a grade 2 endometrioid adenocarcinoma. Immunohistochemical stains were supportive, with positive expression for CK7 and ER, negative for CK20, and only very focally and weakly positive for both CDX2 and p63. Chromogranin, synaptophysin, and TTF-1 were negative. Following surgery, she was treated with five cycles of carboplatin (AUC 6) and paclitaxel (175£¿mg/m2), followed by irradiation. Twenty-six months later, patient continues to be asymptomatic and disease-free. Mixed m¨¹llerian mesodermal tumors mimicking colorectal cancer have been reported in the past. Our case highlights the rarity and the challenges encountered in diagnosing and treating these rare tumors. 1. Introduction Mixed m¨¹llerian mesodermal tumors are rare tumors of uncertain origin. Although these tumors account for 2¨C5% of all uterine malignancies, extragenital mixed m¨¹llerian mesodermal tumors have been reported in various locations ranging from pelvic peritoneum to diaphragm peritoneum. We report a case of a 53-year-old female who presented with chronic constipation and abdominal discomfort for six months. Workup revealed a rectosigmoid mass compatible with a malignant mixed m¨¹llerian mesodermal tumor. Patient was treated with low anterior resection, five cycles of chemotherapy (carboplatin and paclitaxel), and irradiation. 2. Case Report A 53-year-old Portuguese female presented to our hospital with chronic constipation and abdominal discomfort for six months. She denied any change in her appetite or weight. Her past surgical history was significant for a total abdominal hysterectomy with bilateral salpingooophorectomy, performed eight years ago, for uterine fibroids and endometriosis. She denied any postmenopausal or gastrointestinal bleeding. Physical examination revealed an average sized female with no acute distress. Her systemic examination was unremarkable. Laboratory workup revealed hemoglobin 13.1£¿g/dL (normal range: %U http://www.hindawi.com/journals/crionm/2014/948908/