Rectal Metastasis from Breast Cancer - A Case Report and Review of Literature

Q: Why is rectal metastasis from breast cancer often hard to diagnose?

Because gastrointestinal involvement is uncommon and rectal metastases from invasive lobular carcinoma can mimic primary rectal cancer, leading to delayed diagnosis and negative superficial biopsies.

Q: What diagnostic steps led to confirmation in the case?

Pelvic MRI later showed smooth, concentric rectal wall thickening, and repeat colonoscopy with biopsies confirmed metastatic lobular carcinoma after initial superficial biopsies were negative.

Q: Which breast cancer subtype is emphasized as higher risk for GI metastases?

Invasive lobular carcinoma (ILC), which accounts for a minority of primary breast tumors but contributes a much larger proportion of breast-to-GI metastases.

Sep 23, 2026

Uploaded by nayy☆

Metastatic spread of breast cancer to the gastrointestinal tract is rare (<1%), yet it occurs disproportionately often in invasive lobular carcinoma (ILC), where presentation can closely resemble primary rectal malignancy and delay diagnosis. A 40-year-old woman with hormone receptor-positive classic ILC developed rectal obstruction two years after diagnosis; initial superficial biopsies were negative. Later pelvic MRI and repeat deep biopsies confirmed metastatic lobular carcinoma, highlighting the diagnostic value of imaging and deep tissue sampling, especially when new lower-GI symptoms arise after breast cancer.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages18

Reading Time45 min

AccessFree to download

Introduction

Case Presentation

Conclusion

Case Reports in Gastroenterology | Case Rep Gastroenterol 2026;20:311–328 | | | --- | --- | | DOI: 10. 1159/000550604
Received: August 26, 2025
Accepted: January 9, 2026
Published online: July 15, 2026 | © 2026 The Author(s) .
Published by S. Karger AG, Basel [www.karger.com/crg](www.karger.com/crg) | This article is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC) ([https://karger.com/Services/OpenAccessLicense](https://karger.com/Services/OpenAccessLicense)). Usage and distribution for commercial purposes requires written permission. Case and Review Rectal Metastasis from Breast Cancer: A Case Report and Review of Literature Felix-Antoine Coutua Hamila Hagh-Dousta Chelsea Rose Maedler-Krona, c Jamil Asselaha, d Talat Bessissowa, b a Department of Medicine, McGill University, Montreal, QC, Canada; bDivision of Gastroenterology and Hepatology, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada; c Division of Pathology, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada; d Division of Medical Oncology, Department of Medicine, McGill University Health Centre, Montreal, QC, Canada Keywords Rectal metastasis · Gastrointestinal metastasis · Invasive lobular carcinoma · Breast cancer Abstract Introduction: Metastatic spread of breast cancer to the gastrointestinal (GI) tract is very uncommon (<1% of all metastases), but it is disproportionately higher in invasive lobular carcinoma (ILC) compared to invasive ductal carcinoma. Its presentation can mimic primary rectal malignancy, often leading to delayed diagnosis. Case Presentation: We describe a 40-year-old woman with metastatic, hormone receptor-positive classic ILC who developed rectal obstruction 2 years after her breast cancer diagnosis. Initial colonoscopy with superficial biopsies was negative. One year later, pelvic magnetic resonance imaging (MRI) demonstrated smooth, concentric thickening of the rectal wall; repeat biopsies confirmed metastatic lobular carcinoma. Conclusion: This case illustrates the diagnostic challenges posed by rectal metastasis from ILC, especially negative superficial rectal biopsies. Endoscopic and radiologic features often mimic primary rectal pathology, underscoring the importance of deep biopsy and imaging in establishing the diagnosis. New lower-GI symptoms in any breast-cancer survivor, especially one with ILC, should prompt pelvic MRI and deep tissue sampling to exclude metastatic disease if superficial biopsies are negative. © 2026 The Author(s) . Published by S. KargerAG, Basel Correspondence to: Talat Bessissow, talat.bessissow [mcgill.ca](mcgill.ca) Case Reports in Gastroenterology Case Rep Gastroenterol 2026;20:311–328 312 | DOI: 10. 1159/000550604 | © 2026 The Author(s) . Published by S. Karger AG, Basel [www.karger.com/crg](www.karger.com/crg) | | --- | --- | Coutu et al.: Breast Cancer with Rectal Involvement Introduction Breast cancer is the most frequently diagnosed cancer in women worldwide [1]. While bone, liver, lung, and brain are its canonical metastatic destinations [2], gastrointestinal (GI) involvement is documented in <1% of cases [3]. Among reported cases of GI metastases from breast cancer, around half involved the large bowel (cecum, colon, sigmoid, and rectum), and the other half the small bowel (duodenum, jejunum, and ileum). Metastatic involvement of the stomach or anus is exceedingly rare, each occurring in fewer than 1% of cases [4]. Invasive lobular carcinoma (ILC) accounts for roughly 10% of primary breast tumors, yet it contributes 60–80% of breast-to-GI metastases [4, 5]. Loss of E-cadherin in ILC disrupts intercellular adhesion, allowing diffuse single-file (“Indian-file”) infiltration along serosal and submucosal planes and explaining its predilection for hollow viscera, peritoneum, and retroperitoneum [3, 6, 7]. Although rectal deposits represent the mino

FAQs

Why is rectal metastasis from breast cancer often hard to diagnose?

Because gastrointestinal involvement is uncommon and rectal metastases from invasive lobular carcinoma can mimic primary rectal cancer, leading to delayed diagnosis and negative superficial biopsies.

What diagnostic steps led to confirmation in the case?

Pelvic MRI later showed smooth, concentric rectal wall thickening, and repeat colonoscopy with biopsies confirmed metastatic lobular carcinoma after initial superficial biopsies were negative.

Which breast cancer subtype is emphasized as higher risk for GI metastases?

Invasive lobular carcinoma (ILC), which accounts for a minority of primary breast tumors but contributes a much larger proportion of breast-to-GI metastases.

Sep 23, 2026

Uploaded by nayy☆