Nodal Marginal Zone B cell Lymphoma (NMZL)

Epidemiology:

•  rare

Common sites:

• peripheral lymph nodes
• bone marrow
• peripheral blood
• no evidence of extranodal disease (except as above)

Gross features:

Histologic features:

• morphologically resembles lymph node involvement by MALT or splenic marginal zone lymphoma
• infiltration of marginal zone and interfollicular areas
• small lymphocytes:
• marginal-zone B cells
• monocytoid B cells
• small B lymphocytes
• scattered centroblast or immunoblast-like cells
• plasma cell differentiation (some)
• follicular colonization maybe

Immunophenotype:

Molecular features:

• immunoglobulin genes clonally rearranged
• predominance of mutated VH3 and VH4 families
• trisomies 3,18,7
• not associated with translocations of extranodal MZL

Other features:

• patient cannot have a concurrent MALT lymphoma, Hashimoto thyroiditis, or Sjogren syndrome
• indolent behaviour

References:

• WHO Blue Book (2001, 2008)