Break-apart double-color interphase FISH for the detection of breakpoints in the BCL10 locus. (A) Case with cytogenetically proven t(1;14)(p22; q32). The arrow points to a tumor cell in which the dissociation of the red and green signals indicates the presence of a chromosomal breakpoint in the BCL10 locus. The nucleus on the right displays 2 colocalized signals pointing to 2 intact copies of the BCL10 locus. (B) A gastric MALT lymphoma with strong BCL10 nuclear expression. Interphase nuclei from a paraffin section shows that several cells (arrows) display a split of the red and green signals, suggestive of t(1;14)(p22;q32) or variants.