Metastatic gastric carcinoma from breast cancer mimicking primary linitis plastica: A case report.

Metastases to the gastrointestinal tract rarely occur in breast cancer except in invasive lobular carcinoma. The present study reports a rare case of metastatic gastric cancer from invasive ductal carcinoma (IDC) of the breast mimicking primary gastric linitis plastica. A 51-year-old premenopausal female, who had a history of partial mastectomy for right breast cancer at the age of 40, was referred to Toyama City Hospital (Toyoma, Japan) for an endoscopic diagnosis of gastric linitis plastica. Abdominal computed tomography (CT) revealed left hydronephrosis, while peritoneal metastasis and malignant ascites were not detected. Chest CT detected a left lung tumor, which had invaded the left upper bronchus. Biopsy specimens were obtained and the histopathological findings on both the gastric tumor and lung tumor demonstrated poorly differentiated adenocarcinoma, whereas the histology of the original breast cancer was IDC with a solid-tubular type. Immunohistochemistry revealed that the biopsied specimens of the gastric and lung tumors were positive for estrogen receptor (ER), progesterone receptor (PgR) and negative for human epithelial growth factor receptor-2 (HER2). These molecular characteristics indicated the case was metastatic gastric carcinoma from the breast cancer with lung metastasis, since the statuses of ER, PgR and HER2 were concordant with those of the original breast cancer. However, the possibility of primary gastric cancer could not be completely ruled out. Therefore, a total gastrectomy was performed for the purpose of both diagnosis and treatment. Pathological examination of the resected specimen provided a definite diagnosis of multiple metastatic gastric carcinomas from the breast. To the best of our knowledge, metastatic gastric cancer derived from the breast presenting as linitis plastica 11 years following the surgical removal of IDC has not been described previously.