Introduction/Background*Diagnosing cancer during pregnancy is uncommon. Approximately one in every 1000 pregnancies is diagnosed with cancer during the antenatal period. Cervical cancer and breast cancer are among the most commonly identified cancers during pregnancy but gastrointestinal, urological, and lung cancers have a lower rate of incidence.

In this case we discuss successful management of a patient who was diagnosed with carcinoma of ascendant colon during the antenatal period.

Methodology 42 years old women (PARA -0, GRAV -) was admitted in our hospital in 12 weeks gestations because of pain in abdomen. In previous history, before 4 years she had breast cancer surgery when a local tumorectomy was performed with chemotherapy in six cycles. The pregnancy occurred after IVF. She had all symptoms of hyperstimulation syndromes with big ovaries in diameter of 12 cm and ascites. She did not complain any gastrointestinal problem. After two weeks of therapy for hyperstimulation syndromes she had increasing abdominal pain. We performed laparotomy.

Result(s)*After opening the abdomen, we found a tumor of the ascending colon and performed a right hemicolectomy with bilateral ovariectomy. The omentum was full of metastases. We performed a colostomy. Her abdominal pain was lost after surgery. She received five cycle of hemotherapy of FOLOFOX. She was delivered by Caesarean section at the 33^rd weeks of pregnancy. She was discharged on the seven postoperative day because of her good general condition, as well as that of her newborns, two girls.

Conclusion*Carcinoma and pregnancy bring us two main problems. One is to discover right diagnosis and the other is to choose optimal treatment because it requires considerations of both pregnant women and unborn fetus. Colorectal carcinomas are rare and definitive treatment depends on the term of pregnancy. Generally, definitive surgical therapy is offered if the diagnosis is made early in the pregnancy and deferred until after parturition if it made in the late pregnancy. In our case we performed even hemotherapy because of due to the advanced stage of the disease