Abstract
Primary signet ring cell carcinoma (SRCC) of the breast is extremely rare, and the associated patterns of metastatic dissemination poorly described. Here, we report the case of a 61-year-old woman presenting with acute abdominal pain. Esophagogastroduodenoscopy revealed a non-bleeding erosive gastropathy, which was biopsied and found significant for a poorly differentiated, GATA3-positive SRCC. The patient was lost to follow up until re-presenting 6 months later with a perforating duodenal ulcer and umbilical herniation. Biopsies of umbilical hernia sack contents were significant for an estrogen receptor (ER) positive SRCC, and breast examination identified a right breast mass significant for an ER positive lobular carcinoma with signet ring features, thereby affirming the diagnosis of metastatic SRCC of the breast. This case offers insight into an advanced form of a rare clinical entity, and suggests that staining for breast markers such as GATA3 should be considered for all biopsies significant for SRCC.