Primary follicular lymphoma of the gastrointestinal tract: a study of 25 cases and a literature review.

BACKGROUND: To describe better the clinical, biological, endoscopic and pathological presentations, as well as the outcome, of primary follicular lymphoma (FL) of the gastrointestinal (GI) tract.

PATIENTS AND METHODS: From November 1983 to February 2001, 25 eligible patients with primary FL of the GI tract were retrieved from several French Departments of Pathology departments based on histological diagnosis and immunophenotype. Median age was 56 years (range 44-71) with a sex ratio female/male of 2 (17/8).

RESULTS: Abdominal pain was the main presenting symptom followed by intestinal obstruction. The small intestine was the most common site of involvement. Lesions were unifocal in the majority of patients (15/25). A pattern similar to lymphomatous polyposis was observed in 50% (7/14) of patients. Twelve patients had stage I, 10 patients stage II and three patients stage IV disease, and there was minimal extra intestinal involvement. Lymphoma tissues were composed of neoplastic follicles, most of which were grade 1 according to the World Health Organization (WHO) classification. The immunophenotype of the lymphoma cells was CD20+, CD10+, bcl2+ and CD5-. In tissue samples, IgH/bcl2 rearrangement at the MBR locus was present in 11 of 14 patients tested. Seven patients did not receive any treatment; four of them progressed after a median follow-up of 37.5 months. Treatment was otherwise heterogeneous, and complete remission was obtained in 15 patients which lasted for a median of 31 months. Relapses were either in the GI tract (n = 3) or outside the GI tract (n = 3). After a median follow-up of 34 months (range 5-203), 22 patients were still alive (complete remission, 11; partial remission, three; stable disease, six; progressive disease, two).

CONCLUSIONS: Primary FL of the GI tract is a predominantly female lymphoma that most frequently involves the small intestine. Since the endoscopic and clinical presentation may not be different from lymphomatous polyposis, which is often associated with mantle cell origin of tumor cells, it is mandatory to perform an immunohistological and, if possible, a molecular analysis of GI lymphoma. The course of the disease is indolent and does not differ from nodal FL. Thus, therapy may not be required unless significant clinical symptoms are present or until disease progression.