Diffuse gastric cancer with peritoneal carcinomatosis can mimic Crohn's disease.

In some cases the diagnosis of gastric cancer is difficult and the endoscopic presentation may be misleading. Diffuse type gastric carcinoma with peritoneal metastasis may present primarily with abdominal pain, colonic infiltration and/or diarrhea, thus other differential diagnoses like Crohn's disease (CD) may be considered at first. Therefore intensive diagnostic work-up is important. We report two cases of gastric cancer with ascites due to peritoneal carcinomatosis who were first diagnosed as CD. The patients were hospitalized in different institutions for weight loss, abdominal pain and nausea. The first colonoscopy, upper endoscopy with multiple biopsies and ascites puncture were negative for malignant disease, but macroscopic lesions resembling CD were described. Both patients were released on a prednisolone-based treatment for suspected CD. They presented to our hospital for further evaluation due to persistent symptoms. Neither lower nor upper endoscopy were suggestive of CD and endoscopic ultrasound was suspicious of malignancy in one case. Histology was diagnostic and showed gastric infiltration by a poorly differentiated adenocarcinoma. Diffuse type gastric cancer (gastric linitis plastica) with peritoneal metastasis may mimic certain clinical, endoscopic and CT imaging features of CD. Repeated biopsies and endoscopic investigations are often necessary to confirm a malignant process, especially in case of an inconclusive clinical and endoscopic picture. Endoscopic ultrasound may be useful to evaluate the risk of malignancy in patients with macroscopic suspicion of malignancy and negative biopsies.