Metastatic colorectal cancer during pregnancy and postpartum is rather rare, but it represents major diagnostic and therapeutic challenges for obstetricians and surgeons. Cancer itself rarely affects the placenta or growing baby directly. However, metastatic disease is much more common than in nonpregnant patients and detecting cancer while pregnant can be complicated for both the mother and the health care team. In this article, we report a case of moderately differentiated colon adenocarcinoma in pregnancy that was diagnosed in an advanced stage, implying a complex diagnostic and therapeutic approach. The classic histological and immunohistochemical (IHC) study on this case reveals that tumorous areas have lost goblet cells and, implicitly, mucus; also, there are absent estrogen and progesterone receptors, possible causes of neoplasm in pregnancy, the rate of tumor proliferation is increased, the IHC reaction that highlights the protein responsible for cytoplasmatic anchoring of cadherins is intense positive, and the enzyme responsible for inflammation and pain is increased in these areas.