Low-grade follicular lymphoma of the small intestine.

Background: Although the gastrointestinal tract is the most common site of extranodal non-Hodgkin's lymphoma (NHL), primary small intestine lymphomas remain relatively rare, especially localized low-grade follicular B-cell lymphomas. When lymphomas do occur at this site, most are high grade and require aggressive therapy. We report three cases of small intestinal follicular lymphoma diagnosed on endoscopic biopsy and review the clinical history, pathologic features, and treatment outcome.

Study: A review of the medical records and pathology from three cases of small intestine follicular NHL was performed. The pathology specimens were formalin-fixed, paraffin-embedded tissues processed for routine microscopic examination, immunohistochemical staining, and molecular analysis.

Results: Histologic and immunophenotypical studies were diagnostic of grade 1 follicular lymphoma (Revised European-American Lymphoma classification/World Health Organization classification). All cases expressed bcl-2 protein, and polymerase chain reaction analysis supported the diagnosis in two cases with adequate DNA. With 23.3 months' median follow-up, one untreated and one treated patient were alive without symptoms; a third untreated patient died of a nonlymphoma cause.

Conclusion: Isolated indolent lymphomas of the small intestine are rare. Accurate pathologic staging and histologic classification are paramount in delineating treatment options.