Cytogenetic Study of Two Cases with Lymphoma of Mucosa-Associated Lymphoid Tissue J. Whang-Peng, T. Knutsen, E. Jaffe, M. Raffeld, W. P. Zhao, P. Duffey, and D. L. Longo ABSTRACT: Cytogenetic studies have been reported in fewer than 20 patients with lymphoma of mucosa associated lymphoid tissue (MALT). Two patients with this disease at the Clinical Center, National Insti- tutes of Health had numerical and structural chromosome abnormalities, including + 12 in both cases. The clonal karyotypes observed were 48-49,XX, t(2;8)(q33;p23), + 3, - 10,del(10)(q23), + 12, + 18 [cp] and 47,X, -X,i(6p), +7, + inv(12)(p13q13). Review of cytogenetic studies from published data showed that all cases of MALT lymphoma reported to date also have both numerical and structural chromosome abnormalities, the most frequent being numerical involvement of chromosomes 3, 7, and 12. Identification of a clonal abnormality can help establish the diagnosis when differential diagnosis includes atypical hyperplasia. Although trisomy 12 has been associated with a poor prognosis in B-cell chronic lymphocytic lymphoma (B-CLL), both these patients with MALT lymphoma have had long survival: 8 and 11 years, respectively. INTRODUCTION Malignant lymphoma of mucosal-associated lymphoid tis- sue (MALT) is among the new clinically relevant subtypes of non-Hodgkiffs lymphoma (NHL). It is of B-cell origin, usu- ally of low histologic grade, of extranodal origin derived from MALT of the stomach, small intestine, lung, thyroid gland, or lacrimal gland, as well as other extranodal sites [1-7]. The neoplastic cells can infiltrate follicles, on occasion produc- ing a histologic appearance similar to that of follicular lym- phoma [8]. MALT lymphomas have a heterogeneous cyto- logic composition with a spectrum of cells including small lymphocytes, plasma cells, and irregular lymphoid cells that have been termed centrocytelike [9]. The absence of rear- rangements of bcl-1, bcl-2, and c-myc genes helps distinguish MALT lymphomas from other B-cell neoplasms [9, 10], but cytogenetic abnormalities have been reported in fewer than 20 patients [11-14]. Thus, relatively little is known about the molecular or cytogenetic characteristics of this entity. We re- port the cytogenetic characteristics of two MALT lympho- mas diagnosed at the Clinical Center, National Institutes of Health (NIH), Bethesda, Maryland, and review the published data regarding specific chromosome abnormalities in this rare type of lymphoma. From the Medicine Branch (]. W.-P., T. K., ~V. P. Z), Pathology Department (E. ]., M. tt.) and Biological Response Modifiers Pro- gram, (P. D., D. L. L.). NCI, National Institutes of Health, Bethesda, Maryland. Address reprint requests to: Turid Knutsen, Cytogenetic Oncol- ogy Section, NCI Bldg. 10, Rm. 12N-226,National Institutes of Health, Bethesda, MD 20892 USA Received December 23, 1993; accepted April 29, 1994. 74 Cancer Genet Cytogenet77:74-80 (1994) 0165-4608/94/$07.00 CASE HISTORIES Case 1 A 62-year-old white woman was well until June 1982, when she complained of a right submandibular mass associated with swelling, erythema, and pain. Biopsies at that time and again in 1983 were interpreted as reactive. A diagnosis of Sj6greffs syndrome was made in January 1984. A left posterior thoracic skin lesion biopsy in December 1984 was diagnosed as malignant lymphoma of monoclonal B-cell type. Unfor- tunately, the parotid biopsies from 1983 and 1984 were lost before her referral to NIH in January 1985, where she was diagnosed as having stage IV diffuse mixed lymphoma (Work- ing Formulation). Complete remission was obtained with six courses of PROMACE-MOPP (prednisone, adriamycin, methotrexate, cytoxan, etopiside-mechlorethamine, vincri- stone, prednisone, pmcarbazine). Conjunctival relapse in Au- gust 1986 was successfully treated with radiotherapy, but the patient relapsed again in May 1987 with lymphadenopathy and skin involvement. Clinical presentation of pulmonary nodules and hoarseness 1 month later were diagnosed as laryngeal lymphoma and treated with radiotherapy and a sin- gle course of CVP. She was readmitted in August 1989 com- plaining of recurrent fevers (as high as 38.5°C), with no fo- cal infection source. After obvious disease progression was determined, the patient declined further chemotherapy and was discharged, with prednisolone treatment, to her private physician. Case 2 A 55-year-old white woman became ill in August 1985. In April 1986, tissue from a dilatation and curettage, performed because of an 8-month history of episodes of severe vaginal © 1994Elsevier Science Inc. 655 Avenueof the Americas, New York, NY 10010