論文種別 症例報告
言語種別 英語
査読の有無 その他(不明)
表題 Atypical Intestinal Metastases from Invasive Lobular Carcinoma of the Breast: Two Surgical Cases Mimicking Primary Gastrointestinal Tumors.
掲載誌名 正式名:Surgical case reports
略  称:Surg Case Rep
ISSNコード:21987793/21987793
掲載区分国外
巻・号・頁 11(1),pp.25-0554
著者・共著者 Yusuke Kitagawa, Hisanori Miki, Takumi Yamamoto, Yasuhiro Sakai, Jun Watanabe, Yosuke Fukunaga
発行年月 2025
概要 INTRODUCTION:Gastrointestinal metastasis arising from invasive lobular carcinoma (ILC) of the breast is a rare but clinically significant manifestation. Unlike invasive ductal carcinoma, ILC has a higher propensity to metastasize into the gastrointestinal (GI) tract, often presenting with non-specific symptoms and mimicking primary GI tumors. Its accurate diagnosis requires a high index of suspicion and immunohistochemical (IHC) confirmation. Herein, we report 2 cases of intestinal metastases from ILC presenting with bowel stenosis.CASE PRESENTATION:Case 1 involved a 45-year-old woman with no known primary malignancy, who presented with duodenal and small bowel strictures. CT revealed narrowing of the small intestine, along with multiple sclerotic bone lesions. Surgical resection was performed, following which histopathological examination revealed ILC with a characteristic IHC profile (CK7+, CK20-, GATA3+, CDX2-, E-cadherin-). Retrospective breast imaging and biopsy confirmed a diagnosis of primary ILC. Case 2 involved a 57-year-old woman with a known history of luminal-type ILC. At 56 months postoperatively, bone metastasis was detected and PET-CT revealed uptake in the sigmoid colon. Furthermore, colonoscopy demonstrated stricture with no visible mucosal lesions. Surgical resection was subsequently performed, following which IHC confirmed metastatic ILC with a receptor status (ER+, PgR+, HER2-) matching that of the primary tumor.CONCLUSIONS:These cases demonstrate the diagnostic challenges posed by GI metastases arising from ILC, particularly due to submucosal infiltration and lack of endoscopic findings. IHC plays a critical role in differentiating these lesions from primary GI tumors. Although surgical resection may not prolong survival, it is valuable for symptomatic relief and for establishing a definitive diagnosis. Surgeons should be aware of the risk of ILC metastasizing into the GI tract. In patients presenting with atypical intestinal stenosis-particularly those with a history of ILC-metastasis should be considered. In such cases, IHC-guided diagnosis is essential.
DOI 10.70352/scrj.cr.25-0554
PMID 41536970