Invasive Ductal Carcinoma of the Breast Presenting as Small Bowel Obstruction and Ruptured Appendix: A Rare Case Report and Review

Introduction: Metastasis of breast carcinomas to the GI tract is uncommon, and when present is usually of the invasive lobular carcinoma subtype. This case report presents an even more unusual example of invasive ductal carcinoma metastasizing to the GI tract, and with the unusual presentation of a ruptured appendix and Small bowel obstruction. Case presentation: This case report describes a 52-year-old female patient who was diagnosed with metastatic invasive ductal breast carcinoma, which had an extremely unusual presentation of severe abdominal pain, nausea, and vomiting and perforation of the appendix and small bowel obstruction. Although tumors themselves are not an uncommon cause of SBO, metastatic breast cancer is extremely uncommon. Suspicion of breast carcinoma was initially considered after CT scan performed for abdominal pain revealed a previously unknown breast nodule. Subsequent worsening of symptoms, caused by rupture of an appendiceal metastasis, required laparotomy revealed mass of the appendix. Conclusion: This case report and review highlights that it is essential to keep an open mind regarding nonspecific symptoms, and always consider unusual presentations. Early diagnosis from appropriate and timely workup results in better patient outcomes and reduces morbidity and mortality. Invasive Ductal carcinomas of the breast very rarely metastasize to the GI tract, Invasive lobular carcinomas more commonly metastasize to the GI tract whereas invasive Ductal carcinoma metastasizes to lungs and liver. Throughout 23 years reviewing about 8699 appendectomy specimens only about 15 cases of secondary appendiceal tumors were identified.