Synchronous Gastric Metastasis From Sigmoid Colon Cancer: A Case Report

Area of Science:

• Oncology
• Gastroenterology

Background:

• Colorectal cancer is a major global health concern, ranking as the third most common malignancy worldwide.
• While distant metastases to the lung, liver, and bone are common, gastrointestinal tract metastases are exceptionally rare.

Purpose of the Study:

• To report a rare case of synchronous gastric metastasis originating from sigmoid colon cancer.
• To emphasize the importance of considering metastatic gastric cancer in patients with other solid organ malignancies.

Main Methods:

• A 78-year-old male patient presented with synchronous diagnoses of sigmoid colon cancer and gastric cancer.
• Surgical intervention involved simultaneous radical subtotal gastrectomy and anterior resection.
• Immunohistochemical (IHC) analysis was performed on resected specimens.

Main Results:

• Postoperative pathology confirmed moderately differentiated adenocarcinoma in both the sigmoid colon and stomach.
• IHC analysis of gastric specimens revealed tumor cells positive for cytokeratin 20 (CK20) and caudal-type homeobox gene 2 (CDX2), and negative for CK7.
• These IHC findings confirmed the gastric lesion as a metastasis from the sigmoid colon cancer.

Conclusions:

• Gastric metastasis from colorectal cancer, though infrequent, can occur synchronously.
• Clinicians must maintain a high index of suspicion for metastatic gastric cancer in patients with other solid organ malignancies.