Case Presentation: Breast cancer accounts for approximately 266,000 cases each year and is responsible for over 40,000 deaths in the United States. The most common sites of metastasis include bone, liver, lungs and brain. The estimated incidence rate of breast cancer metastases to the stomach is only 0.3%. Diagnosis of gastrointestinal metastasis can be complicated by its infrequency and morphological resemblance to primary gastrointestinal neoplasms.
Case Presentation: We present a case of an 83 year old female who presented to our emergency department with complaints of nausea and vomiting for 4 days. Her medical history included mastectomy for right sided lobular carcinoma of the breast 10 years ago. She had been treated with anastrozole for 5 years and yearly mammograms had been negative for recurrence. The patient complained of inability to tolerate oral intake for the past 4 days. Computed tomography of the abdomen revealed a dilated stomach with the dilation extending to the antrum and duodenal bulb. She underwent an upper endoscopy with endoscopic ultrasound. Gastric stenosis was found at the pylorus and duodenal bulb which was dilated with a balloon. Gastric biopsies showed metastatic breast adenocarcinoma and further testing revealed ER, PR positivity and HER2 negativity. The patient was initiated on Fulvestrant for treatment of metastatic breast adenocarcinoma as an outpatient. Two months later she was readmitted to hospital with septic shock and was eventually transitioned to hospice.
Interestingly, the patient had a similar presentation 8 months ago. An upper endoscopy had shown grade D esophagitis and moderate pyloric stenosis. Gastric biopsies had revealed inactive gastritis. The patient was discharged home with instructions for a repeat upper endoscopy with endoscopic ultrasound in 6 months. However, she did not follow up until her next presentation to the emergency room.
Discussion: This case highlights the importance of keeping a broad differential for cases presenting with gastric outlet obstruction. A diagnosis of breast cancer metastases to the gastrointestinal tract is often difficult because of its low incidence. Differentiating metastatic breast carcinoma from primary gastric adenocarcinoma cannot be done using histological examination alone and superficial biopsies may not be accurate. Immunohistochemistry is needed to differentiate the two based on staining for estrogen and progesterone receptors.
Conclusions: It is vital to distinguish between breast cancer metastasis to the stomach and primary gastric cancer because treatment for the metastatic tumor usually involves systemic chemotherapy rather than a local treatment for gastric lesions. Therefore, clinicians attending to patients with a history of lobular breast carcinoma should have a high index of suspicion for the diagnosis to prompt an early investigation before the disease progresses further.