Metastatic invasive lobular carcinoma of breast with gastric carcinoma as the first manifestation: A case report and review of the literature

Invasive lobular carcinoma(ILC)is the second frequently diagnosed breast cancer with a low incidence of gastric metastasis. And metastatic ILC of breast with gastric tumor as the first symptom is more rare. Therefore, immunohistochemistry is the key to correct diagnosis. We reported a 45-year-old female patient who developed nonspecific systemic symptoms firstly. Imaging examination showed diffuse thickened gastric wall, and gastroscopic biopsy revealed a poorly differentiated adenocarcinoma. Twelve months after the diagnosis, a mass was found in the patient's left breast and was diagnosed as ILC on biopsy. Combined with the patient's medical history and immunohistochemistry results, the final diagnosis of metastatic ILC was made on gastroscopic biopsy. The clinicopathological characteristics of breast ILC with gastric metastases were reviewed in the light of the literature, and differentiated from primary poorly differentiated adenocarcinoma of the stomach to improve the clinicians' understanding. It could be a real challenge to differentiated patients with gastric metastasis of breast cancer from primary poorly differentiated adenocarcinoma of the stomach. Therefore, to improve the awareness of the clinicians, and to guide the choice of clinical treatment options, we should have an intimate knowledge of the clinicopathological characteristics of gastric metastases in breast ILC combining with the literatures.