BCL10 expression and localization in Ocular Adnexa MALT lymphomas: a comparative cytogenetic and immunohistochemical study

Abstract

Summary. T(1;14) (p22;q32) involving BCL10 and IGH genes is a rare but recurrent chromosomal aberration in MALT-type lymphoma. It is rarely described in ocular adnexa B cell lymphomas, although nuclear BCL10 shuttling seems to be critical for disease progression in this district. We have evaluated the translocations MALT lymphoma-related in a series of 45 ocular adnexa cases, focusing in particular on their relation with BCL10 expression and its cellular topographic distribution. A prognostic tissue microarray (TMA) with ocular adnexa MALT lymphomas was designed. A study of BCL10 expression and its topographic distribution was performed through immunohistochemistry. In addition the assessment of t(14;18) (q32;q21), t(1;14) (p22;q32) and t(11;18) (q21;q21) was determined by Fluorescent In Situ Hybridization (FISH). Our series revealed t(14;18) (q32;q21) in 6/43 cases (14,3%). t(1;14) (p22;q32), never described in ocular adnexa MALT lymphomas, was observed in 3/31 (9,7%), two of which exhibited the gain of 3’ upstream BCL10 gene signal (4%), whereas no case showed t(11;18) (q21;q21). Moreover, BCL10 expression was observed in 18/45 cases. In particular its nuclear expression was revealed in 12/45 cases, cytoplasmic expression in 5/45 and both cytoplasmic and nuclear expression in 1/45. Statistical analysis demonstrated that while BCL10 cytoplasmic expression is significantly related to the presence of the investigated chromosomal aberrations, in particular with t(14;18) (q32;q21), BCL10 nuclear shuttling does not show any correlation with these translocations. Our data support that BCL10 nuclear distribution is neither related to BCL10 rearrangement nor to other known translocations.