We present the case of a 70-year-old male who consulted for abdominal pain, vomiting, fever, and signs of peritoneal irritation. Histopathology showed goblet-like cells organized in nests, without tubules, with transmural infiltration. Immunohistochemistry was positive for synaptophysin and chromogranin, and a grade-3 goblet-cell adenocarcinoma (GCA) was diagnosed.