Gastric pseudolymphoma with monotypic cytoplasmic immunoglobulin

Area of Science:

• Gastroenterology
• Pathology
• Immunology

Background:

• Pseudolymphoma of the stomach is a benign lymphoid proliferation.
• Distinguishing it from malignant lymphoma can be challenging.
• Immunohistochemistry aids in characterizing lymphoid lesions.

Observation:

• Two young patients presented with gastric hyperplastic lymphoid lesions.
• Initial diagnosis was pseudolymphoma based on histology.
• Immunoperoxidase staining revealed monotypic cytoplasmic immunoglobulin (lambda/IgM and lambda/IgG).

Findings:

• The cases demonstrate monoclonal but reactive lymphoid hyperplasia, termed monoclonal-type pseudolymphoma.
• Germinal center staining was monotypic in one case and polytypic in the other.
• This suggests a spectrum of B-cell clonality within reactive lesions.

Implications:

• Monoclonal pseudolymphoma requires vigilant monitoring for malignant transformation.
• Accurate diagnosis is critical for appropriate patient management.
• Further research into the pathogenesis of these lesions is warranted.