Metastatic Neoplasms Involving the Stomach

Area of Science:

• Gastroenterology
• Oncology
• Pathology

Background:

• Metastatic neoplasms to the stomach are uncommon and pose diagnostic challenges, especially when primary malignancy history is unknown.
• Accurate identification of gastric metastases is crucial for patient management and treatment planning.

Purpose of the Study:

• To determine the most frequent tumors metastasizing to the stomach.
• To identify morphological features aiding in the diagnosis of gastric metastases and prediction of primary tumor sites.

Main Methods:

• Retrospective review of 150 patients with metastatic neoplasms involving the stomach.
• Analysis of H&E and immunohistochemical stains, alongside clinical, endoscopic, and radiologic data.

Main Results:

• Epithelial tumors (73.3%) were the most common, followed by melanoma (20.6%).
• Lobular breast carcinoma was the most frequent in women; melanoma in men.
• A solid/diffuse growth pattern (75%) was more common than glandular morphology, seen in lobular breast carcinoma, melanoma, and renal cell carcinoma.

Conclusions:

• Metastatic neoplasms should be considered in gastric neoplasm differential diagnoses, especially those with a diffuse/solid pattern.
• Müllerian neoplasms are exceptions among glandular tumors, often exhibiting a papillary/micropapillary architecture distinct from primary gastric cancers.