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© 1999 American Society for Clinical Oncology
Primary Low-Grade Lymphomas of the IntestineArthur Skarin, MD, Consultant Editor
University Departments of Medicine, Pathology, and Radiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong CASE 2: PRIMARY FOLLICULAR LYMPHOMA OF THE COLON A 47-year-old man presented with a palpable mass in the left upper quadrant of the abdomen. Physical examination did not reveal any peripheral lymphadenopathy. An abdominal computed tomography scan showed a large mass, which measured 10 x 8 x 6 cm, arising from the splenic flexure of the colon (Fig 1, M). There was infiltration of the surrounding pericolic fat, enlarged pericolic lymph nodes, and thickening of Gerota's fascia and the lateral conal fascia (Fig 1, arrows). These features suggested transmural involvement. A separate pedunculated mass was also noted to arise from the wall of the ascending colon (Fig 1, X). Laparotomy showed three separate tumor masses measuring 10 cm, 5 cm, and 1.5 cm in diameter in the splenic flexure, cecum, and ascending colon, respectively, associated with multiple enlarged pericolic lymph nodes adjacent to the tumor masses. A transverse colectomy and an ascending colectomy with end-to-end colonic and ileocolonic anastomoses were performed.
The colectomy specimen showed transmural infiltration by follicular (follicle center cell) lymphoma (Fig 2). The tumor was composed of diffuse sheets and nodular aggregates of lymphoid cells with patchy necrosis and ulceration. The infiltrate consisted of a mixture of small- to medium-sized cleaved centrocytes and scattered, large, noncleaved centroblasts (Fig 3) that were positive for L26 (CD20) (Fig 4) and bcl-2 (Fig 5) but negative for CD3, CD5, and cyclin D1. Lymphoepithelial lesions were absent. DNA extracted from paraffin-embedded specimens was analyzed for the t(14;18) translocation by a seminested polymerase chain reaction (PCR) with external1 and internal2 forward primers and a consensus backward JH primer. The PCR assay revealed the presence of a band measuring about 120 base pairs (Fig 6, M, size marker; lane I, positive control; lanes II and III, colectomy sample in duplicate; lane IV, reagent blank); PCR for the t(11;14)3 was negative.
A complete blood picture showed a hemoglobin level of 12.8 g/dL (normal range [NR], 11.5 to 16.5 g/dL), a platelet count of 393 x 109/L (NR, 150 to 400 x 109/L), and a leukocyte count of 10.1 x 109/L (NR, 4 to 11 x 109/L) with a normal differential. The lactate dehydrogenase level was 701 U/L (NR, < 400 U/L). Bilateral bone marrow biopsies revealed no lymphomatous infiltration. The patient achieved complete remission with six courses of fludarabine, mitoxantrone, and dexamethasone.4 The diagnosis of follicular lymphoma in our patient is based on histology (cell morphology and the presence of a follicular pattern), immunophenotyping (CD20+, CD3-, CD5-), bcl-2 protein expression in the neoplastic follicles,5 and the detection of the t(14;18) by PCR. Mantle-cell lymphoma is a differential diagnosis in our patient, but it was excluded by the absence of CD5 and cyclin D1 immunoreactivity as well as the absence of t(11;14) by PCR.3 Indeed, the immunohistochemical staining for enhanced bcl-2 expression in the neoplastic but not in the reactive germinal centers helps to distinguish follicular lymphoma from follicular hyperplasia of the mucosa-associated lymphoid tissue.6 Follicular lymphoma is the most common type of lymphoma among adults in Western countries, comprising 35% to 40% of all non-Hodgkin's lymphomas.5,7 In contrast, a low incidence of 13% was reported among the Chinese population in Hong Kong.8 Patients are often elderly and typically present with widespread nodal disease at diagnosis, frequently with involvement of the liver, spleen, and bone marrow.5,7 In contrast, primary extranodal follicular lymphoma without peripheral lymphadenopathy is uncommon. Although the gastrointestinal tract is the most common site for primary extranodal lymphoma, only about 10% of such cases involve the colon, with the majority arising in the stomach. Among this group of tumors, follicular lymphoma arising in the gastrointestional tract is rare, constituting only 1% to 3% of extranodal lymphomas of the gut in large series.6
REFERENCES 1. Horseman DE, Gascoyne RD, Couland RW, et al: Comparison of cytogenetic analysis, Southern analysis and polymerase chain reaction for the detection of t(14;18) in follicular lymphoma. Am J Clin Pathol103:472-478, 1995[Medline]
2.
Crescenzi M, Seto M, Herzig GP, et al: Thermostable DNA polymerase chain amplification of t(14;18) chromosome breakpoints and detection of minimal residual disease. Proc Natl Acad Sci U S A85:4869-4873, 1988 3. Chim CS, Chan ACL, Choo CK, et al: Mantle cell lymphoma in Chinese: Clinicopathological features and treatment outcome. Am J Hematol59:295-301, 1998[Medline]
4.
McLaughlin P, Hagemeister FB, Romaguera JE, et al: Fludarabine, mitoxantrone and dexamethasone: An effective new regimen for indolent lymphomas. J Clin Oncol14:1262-1268, 1996 5. Harris NL, Ferry JA: Follicular lymphoma and related disorders (germinal center lymphoma), Knowles DM (ed):Neoplastic Hematopathology645-674Baltimore, MD, Williams & Wilkins, 1992 6. LeBrun DP, Kamel OW, Cleary ML, et al: Follicular lymphoma of the gastrointestinal tract. Am J Pathol140:1327-1335, 1992[Abstract] 7. Shipp MA, Mauch PM, Harris NL: Non-Hodgkin's lymphomas, in DeVita VT, Hellman S, Rosenberg SA (eds): Cancer. Philadelphia, PA, Lippincott-Raven, 1997, pp 2165-2199 8. Ho FCS, Todd D, Loke SL, et al: Clinico-pathological features of malignant lymphomas in 294 Hong Kong Chinese patients: Retrospective study covering an eight-year period. Int J Cancer34:143-148, 1984[Medline]
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Copyright © 1999 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
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