[Signet ring cell infiltrate in the colon and gastric mucosa].

A 49-year-old female patient presented with anemia of unclear origin (hemoglobin level 6 µg/dl). During coloscopy a circular wall edema in the right flexure of the colon was observed and gastroduodenoscopy gave rise to the suspicion of fundic gland polyps (Elster's cysts) of the mucosa. In the lamina propria of the gastric mucosa, infiltration of a poorly differentiated carcinoma with signet ring cell morphology could be histologically identified resulting in the suspected diagnosis of a primary gastric signet ring carcinoma. Using immunohistochemistry it could be shown that the tumor cells expressed cytokeratin 7 (CK7), estrogen receptors and Gata 3 but not CK20 or Cdx2. The diagnosis of metastases of lobular breast cancer in the gastric and colon mucosa could be made.