Complex karyotype involving six chromosomes, with one dicentric and three yet unreported acquired chromosomal aberrations in a case of splenic marginal zone lymphoma

Abstract

BackgroundSplenic marginal zone lymphoma (SMZL) is an extremely rare low-grade malignancy of the B-cells, comprising <2% of all non-Hodgkin lymphoma (NHL). SMZL occurs at a median age of 65years while the median survival has been recorded to be approximately 10.5years. Clinically, it is associated with splenomegaly, moderate lymphocytosis and sometimes autoimmune thrombocytopenia and/or anemia; also cytopenias and are frequently observed.The pathogenesis of SMZL still remains unclear. Approximately 70–80% of cases have been reported to exhibit detectable cytogenetic and/or molecular genetic abnormalities. The most frequent cytogenetic abnormalities are deletions in 7q22–q32, followed by gain of chromosomes 3/3q, 5q, 9q, 12q and 20q, and deletion in 17p. Complex karyotypes are common: the most frequently involved chromosomes are 1, 3, 7, 8, and 14. However, the incidence of specific recurrent clonal cytogenetic abnormalities in SMZL has not been established yet. ResultsBone marrow of a 78-year-old male patient with a 1month history of umbilical abdominal pain, cough, pallor, vomiting, fever, pancytopenia, anemia and enhanced serum lactate dehydrogenase (LDH) level was studied by banding cytogenetics, refined by fluorescence in situ hybridization including array-proven multicolor banding. A complex karyotype involving, among others both chromosomes 13, was detected. An unbalanced translocation der(13)t(1;13)(q21;p11.2) led to partial trisomy of 1q21-qter and a dicentric dic(13)t(3;13)(p11.2;p11.2) caused partial trisomy of 3q11.2-qter. Besides there were inversion inv(1)(p12q12) and a balanced translocation t(9;14)(p13;q32.3) as yet unreported abnormalities in an adult SMZL case at diagnosis. The immunophenotype was consistent with marginal zone lymphoma according to World Health Organization (WHO) recommendations. ConclusionsTo the best of our knowledge, a comparable adult SMZL case with complex karyotype, anemia and elevated LDH was not previously reported. Besides the involvement of yet unreported genetic regions in SMZL, also this case is one of the rare examples for a malignancy with a stable dicentric chromosome.