Esophageal Neoplasm with Breast Metastasis: Case Report

Introduction:  Esophageal cancer is the seventh most frequently diagnosed cancer and the sixth leading cause of cancer-related death worldwide. In Brazil, it ranks 13^th among the most common types of cancer. The most usual sites of metastatic esophageal cancer are lungs, liver, and bones. Metastases from esophageal cancer to the breast are extremely rare and poorly documented in the literature.

Case report:  A 45-year-old man was diagnosed with esophageal adenocarcinoma after presenting with dyspepsia and epigastralgia. Investigation via upper gastrointestinal endoscopy revealed esophageal adenocarcinoma with no distant metastases. He underwent esophagectomy and adjuvant chemotherapy. Post-treatment positron emission tomography (PET-CT) detected local recurrence, leading to the initiation of palliative therapy. Shortly before, a nodule in the right breast was initially diagnosed as a primary breast lesion, triple-negative carcinoma of no special type. However, a review of the slide revealed poorly differentiated metastatic adenocarcinoma from the esophagus, resulting in two discordant diagnoses. A third analysis of the breast material by immunohistochemistry confirmed a secondary metastatic lesion from the esophagus. During treatment, the patient had a seizure, with diagnosis of secondary brain implant. He underwent radiotherapy for the central nervous system lesion and mastectomy. PET-CT revealed no signs of abnormal metabolic activity. He is currently asymptomatic with therapeutic maintenance immunotherapy associated with HER2 blockade.

Conclusion:  This case highlights the rarity of breast metastasis in esophageal cancer and the crucial importance of immunohistochemistry for an accurate differential diagnosis and adequate therapeutic planning.

Key words:
Esophageal Neoplasms; Adenocarcinoma; Neoplastic Metastasis; Breast Neoplasms; Immunohistochemistry