title: Breast Cancer Metastasis to the Stomach That Was Diagnosed after Endoscopic Submucosal Dissection.
abstract: A 52-year-old woman presented with stage IIB primary breast cancer (cT2N1M0), which was treated using neoadjuvant chemotherapy (epirubicin, cyclophosphamide, and paclitaxel). However, the tumor persisted in patchy areas; therefore, we performed modified radical mastectomy and axillary lymph node dissection. Routine endoscopy at 8 months revealed a depressed lesion on the gastric angle's greater curvature, and histology revealed signet ring cell proliferation. We performed endoscopic submucosal dissection for gastric cancer, although immunohistochemistry revealed that the tumor was positive for estrogen receptor, mammaglobin, and gross cystic disease fluid protein-15 (E-cadherin-negative). Therefore, we revised the diagnosis to gastric metastasis from the breast cancer.
authors.affiliation: Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Masahide
authors.initials: M
authors.lastname: Kita
authors.affiliation: Department of Breast and Endocrine Surgery, Okayama University Hospital, Okayama, Japan.
authors.forename: Masashi
authors.identifier: 0000-0001-8102-9072
authors.initials: M
authors.lastname: Furukawa
authors.affiliation: Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Masaya
authors.identifier: 0000-0002-1757-5754
authors.initials: M
authors.lastname: Iwamuro
authors.affiliation: Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Hori
authors.affiliation: Department of Endoscopy, Okayama University Hospital, Okayama, Japan.
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Kawahara
authors.affiliation: Department of Breast and Endocrine Surgery, Okayama University Hospital, Okayama, Japan.
authors.forename: Naruto
authors.initials: N
authors.lastname: Taira
authors.affiliation: Department of Breast and Endocrine Surgery, Okayama University Hospital, Okayama, Japan.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Nogami
authors.affiliation: Department of Breast and Endocrine Surgery, Okayama University Hospital, Okayama, Japan.
authors.forename: Tadahiko
authors.initials: T
authors.lastname: Shien
authors.affiliation: Department of Pathology, Okayama University Hospital, Okayama, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Department of Breast and Endocrine Surgery, Okayama University Hospital, Okayama, Japan.
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Doihara
authors.affiliation: Department of Gastroenterology and Hepatology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okada