Primary duodenal follicular lymphoma successfully treated with rituximab

Systemic follicular lymphoma with massive intestinal involvement with leukemic manifestation

A 30-year-old man was referred to our hospital with leukocytosis and fecal occult blood. His white blood cell count was 30.2 × 10(9)/L with 79% small- to medium-sized lymphocytes. Surface antigen analysis revealed that these lymphocytes were positive for CD19, CD20, CD10, and CD23, but negative for CD5. The lymphocytes infiltrated the bone marrow. On endoscopic examination of the duodenum and jejunum, many small polypoid lesions were observed. A histologic picture of a biopsied lesion showed diffuse infiltration of small- to medium-sized lymphocytes in the submucosal region. On immunohistochemistry, these lymphocytes were positive for CD20, BCL2, and CD10 (weakly). Polymerase chain reaction analysis of cells from peripheral blood, bone marrow, and intestinal lesion showed a fusion product of BCL2 and immunoglobulin heavy chain (IGH) genes. The fused BCL2/IGH gene was also demonstrated by fluorescence in situ hybridization in the same cell sources. Computed tomography scanning showed marked wall thickening throughout the small intestine and enlarged mesenteric lymph nodes. A diagnosis of follicular lymphoma with massive intestinal involvement in a leukemic state was made. After 6 courses of rituximab-combined CHOP chemotherapy, complete remission was obtained.

Gastrointestinal follicular lymphoma: review of the literature

Gastrointestinal follicular lymphoma (GI-FL) is a relatively rare disease, accounting for only 1%-3.6% of gastrointestinal non-Hodgkin's lymphoma. Although the duodenum and terminal ileum are considered to be the most common sites of origin, the development of wireless capsule endoscopy and double-balloon enteroscopy has increased the detection of GI-FL in every part of the small intestine. Approximately 70% of patients with GI-FL are estimated to have multiple lesions throughout the entire gastrointestinal tract. FL is a low-grade lymphoma that usually develops very slowly. If the lymphoma causes no symptoms, immediate treatment may not be necessary. Standard therapy has not yet been established for GI-FL, but chemotherapy, radiotherapy, monoclonal antibody therapy, or a combination of these therapies, is sometimes performed based on the therapeutic regimens for nodal FL. Regimens including conventional chemotherapy with rituximab, which achieve high response rates in nodal FL, are commonly used for GI-FL. The long-term clinical outcome of GI-FL is unclear. The results of a few series on the long-term outcomes of patients with GI-FL treated with conventional therapy indicate a median relapse-free time ranging from 31 to 45 months. On the other hand, in patients with GI-FL who were followed without treatment, the median time to disease progression was 37.5 months. Thus, whether to initiate aggressive therapy or whether to continue watchful waiting in patients with GI-FL is a critically important decision. Ongoing research on biomarkers to guide individualized GI-FL therapy may provide invaluable information that will lead to the establishment of a standard therapeutic regimen.

Follicular lymphoma of the duodenum: a clinicopathologic analysis of 26 cases

OBJECTIVE

Follicular lymphomas (FLs) occur commonly in the lymph nodes, and duodenal FL (DFL) is reported to be rare.

METHODS

We analysed the clinical, morphological, immunohistochemical and genetic features of 26 cases of DFL. Primary DFLs and systemic FLs that involved the duodenum at any point during the clinical course were included in the analysis.

RESULTS

Typically, primary DFLs (14 cases) were found incidentally at routine medical check-ups, whereas involvement of the duodenum by systemic FLs (12 cases) was found through staging procedures. All cases involved the second portion of the duodenum. Helicobacter pylori infection was common (71%). In all cases, the histologic grade was low (either grade 1 or 2), and CD20, CD10 and Bcl-2 were positive by immunohistochemistry. Immunoglobulin heavy chain gene (IGH) and bcl-2 gene (BCL2) fusion was frequently shown by fluorescence in situ hybridization (FISH) analysis: nine of 12 cases (75%) of primary DFL and 10 of 12 cases (83%) of systemic DFL were positive. Treatment regimens employed were rituximab (R) plus chemotherapy (10), R (6), chemotherapy (3), irradiation (3) and the other three patients were subjected to observation. After a median follow-up duration of 40 months (ranging 11-96 months), 17 patients were alive without disease, seven were alive with disease and one had died of lymphoma.

CONCLUSIONS

Primary DFLs resemble systemic and nodal FLs, except that the former has high incidence of early stage and low-grade histology. The duodenum appears to be a frequently involved extranodal site of FL with IGH/BCL2.