Epstein-Barr virus-associated high-grade B-cell lymphoma of mucosal-associated lymphoid tissue in a 9-year-old boy

We report an unusual case of Epstein-Barr virus (EBV)associated mucosal-ass ociated lymphoid tissue (MALT) lymphoma involving the lungs, kidneys, and a xillary lymph nodes in a child with congenital hypoadrenalism and panhypopi tuitarism. The patient presented with an aggressive clinical course and his tologic evolution. Initial biopsies (1994) of the lung and kidney revealed histologic features of low-grade B-cell MALT lymphoma with lymphoepithelial lesions within the renal tubules and bronchial epithelium. Subsequent biop sies (1996, 1997, and 1999) revealed progressively greater cytologic atypia , polymorphism, and necrosis; an increased mitotic rate; and a preponderanc e of large cells, indicative of progression from a low-grade to a high-grad e MALT lymphoma. Immunophenotyping of the lung and lymph node lesions revea led identical surface marker profiles: cells were CD19(+), CD20(+), immunog lobulin (Ig) G(+), kappa(+), lambda(-), CD5(-), CD10(-), CD23(-), and IgM(- ), and also negative for T-cell markers. Genotypic analysis demonstrated th e presence of immunoglobulin heavy chain rearrangement and monoclonality of EBV in the lung lesion by Southern blot hybridization and polymerase chain reaction (PCR). The clinicopathologic features suggest that these lesions might represent an immunosupression-related continuum of low-grade to high- grade MALT lymphomas. Infection with EBV may have contributed to this tumor 's aggressive clinical and histologic evolution.