S3168 Metastatic Breast Cancer to a J-Shaped Muscular Bag – The Stomach

Abstract

Introduction: Female breast cancer was the leading cause of global cancer incidence in 2020, with an estimated 2.3 million new cases, representing 11.7% of all cancer cases. The most common primary target sites of breast cancer metastasis are bone, lung, liver, and brain. The stomach is an infrequent site of breast cancer metastasis, accounting for an incidence ranging from 0.3% in retrospective studies to 8-18% in autopsy series. Needless to say, metastasis to the stomach from any primary tumor is itself atypical, with an incidence of 0.2-1.7%. We present a case of breast cancer metastasis to the stomach from a rare histological subtype of breast cancer- glycogen-rich, clear cell breast carcinoma. Case Description/Methods: 75- year-old female with clear cell glycogen rich invasive carcinoma, stage IIIB of the right breast presented to the emergency department (ED) complaining of fatigue and weakness for two days. Vital signs were normal. Physical examination revealed ataxic gait and right-sided hemiparesis. Labs showed a hemoglobin of 7.5 g/dl (baseline 9.8 g/dl) and hematocrit 23.5% (baseline 30%). The following day her hemoglobin asymptomatically dropped to 6.8 g/dl, and a repeat reading showed a further decline to 5.8 g/dl. Two units of packed red blood cells (PRBC) were transfused, which increased her hemoglobin to 7.8 g/dl. Fecal Occult Blood Test (FOBT) was positive, and gastroenterology was consulted to investigate further. Computerized Tomography (CT) of the abdomen showed a 4.4 cm intraperitoneal mass in the left mid-abdomen highly suggestive of metastasis. Esophagogastroduodenoscopy (EGD) revealed several gastric ulcers on the greater aspect of the stomach's body located on the mucosal mound or raised mucosa (Figure 1). Given the undermining margins and the ulcer's location, there was increased suspicion for malignancy and she was diagnosed with metastatic poorly differentiated gastric adenocarcinoma. Due to the patient's low-performance status, hospice/palliative care was pursued. Discussion: The exact mechanism of gastric metastasis of breast cancer is still unclear. Gastric metastasis can have a negative impact on survival and must be investigated in patients with breast cancer who present with non-specific gastrointestinal symptoms. There should be a very high index of suspicion for a prompt diagnosis. In patients with a history of breast cancer, gastric endoscopy should be offered in cases of GI symptoms, even when the symptoms are vague.Figure 1.: Gastric perforation secondary to malignant gastric outlet obstruction.