Primary Nodal Marginal Zone B-cell Lymphoma: Clincopathologic Analysis of Splenic and Mucosa-Associated Lymphoid Tissue Type

ABSTRACT

BACKGROUND: Primary nodal marginal zone B-cell lymphoma (MZBL) is recently divided into mucosa-associated lymphoid tissue (MALT) type and splenic type. Herein, we analyzed clinicopathologic differences of those two types of nodal MZBL. METHODS: Histologic and clinical findings of eleven cases of primary nodal MZBL lymphoma were reviewed. Immunohistochemical stains for IgD, Ki-67, CD3, and CD20 were performed. RESULTS: The cases were classified as splenic type in four, MALT type in five, and unclassified in two. The age at presentation was 36.7 years old (range 16-73) in splenic type and 48 years old (range 31-68) in MALT type. Two patients with splenic type and one with MALT type had a long history of lymphadenopathy up to 9 years. Whereas tumors of splenic type showed nodular infiltration of tumor cells with follicular colonization and hyperplastic germinal center, tumors of MALT type showed mainly sinusoidal or parafollicular infiltration and atrophic germinal centers. All the patients with splenic type were alive at last follow-up and one patient with MALT type died of disease at 5 months after diagnosis. CONCLUSIONS:Although the number of cases we analyzed was small, splenic type seems to be distinct from MALT type and lower grade neoplasm.