Nuclear bcl10 expression characterizes a group of ocular adnexa MALT lymphomas with shorter failure-free survival

Abstract

Ocular adnexa B-cell lymphomas are a relatively rare group of extranodal lymphomas, marginal-zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT lymphomas) being the most frequent type at this location. As with other nongastrointestinal MALT lymphomas, ocular adnexa MALT lymphomas have distinct characteristics from those of the gastric MALT model, implying specific pathogenic events, which could be of interest in the prediction of clinical behavior and the choice between therapeutic options. In a series of 39 cases of ocular adnexa MALT lymphomas, studied using a tissue microarray, we observed that the most frequent alteration was related to apoptosis regulation. Thus, caspase 3 activity was completely abolished, and phosphorylated IκBα, a marker of NF-κB activation, showed increased expression, while cases with an increased number of large cells displayed increased expression of survivin and other cell-cycle-related proteins, such as cyclin A, cyclin E and Ki67, and p16 expression was reduced. There were no occurrences of t(11;18)(q21,q21), while 5/37 cases exhibited t(14;18)(q32;q21). Aberrant nuclear expression of bcl10 was observed in 11 cases, independently of the presence of translocations, and was significantly associated with phosphorylated IκBα expression and a reduced TdT-mediated biotin-dUTP nicked-end labeling apoptotic index. Moreover, patients with tumoral bcl10 nuclear expression showed shorter failure-free survival.