Gastric pseudolymphoma. Its three subtypes and relation to lymphoma

Area of Science:

• Gastroenterology
• Surgical Pathology
• Oncology

Background:

• Gastric pseudolymphoma (GPL) is a rare benign lymphoid proliferation of the stomach.
• Understanding its distinct histologic types and relationship to gastric lymphoma is crucial for accurate diagnosis and management.
• Previous studies have described GPL, but further clarification on diagnostic criteria and malignant potential is needed.

Purpose of the Study:

• To describe three distinct histologic types of gastric pseudolymphoma.
• To establish criteria for the common inflammatory type of GPL.
• To evaluate the potential of GPL as a precursor lesion to gastric lymphoma.

Main Methods:

• Histologic classification of ten cases of gastric pseudolymphoma into three types: inflammatory, nodular lymphoid hyperplasia, and angiofollicular lymphoid hyperplasia.
• Review and summarization of 175 previously reported cases from the literature.
• Emphasis on evaluating nuclear cytology and mitotic rate for accurate diagnosis, differentiating from chronic lymphocytic leukemia.

Main Results:

• Three histologic types of GPL were identified and described.
• Criteria for the common inflammatory type were refined, confirming previous findings.
• Gastric pseudolymphoma accounts for an estimated 10-15% of gastric lymphoid tumors, typically presenting earlier and smaller than gastric lymphoma.
• Five cases showed associated focal lymphoma, suggesting a precursor relationship.

Conclusions:

• Gastric pseudolymphoma is a distinct entity with identifiable histologic subtypes.
• GPL may represent a precursor lesion with malignant potential, necessitating careful pathological evaluation.
• Extensive pathologic sampling and complete surgical excision are recommended for cases of gastric pseudolymphoma.