MALT lymphoma

Cells are characteristic medium-sized with round to slightly indented nucleus, dispersed chromatin and abundant pale cytoplasm, leading to a monocytoid appearance. Sometimes there is a plasmacytic differentiation (cutaneous MALT and thyroid MALT).
There are no specific immunephenotypical markers for MALT lymphoma, but the absence of CD5 is usefull in distinction to MCL and CLL and CD10 in the exclusion for FCL.