marginal zone B-cell lymphoma of nodal type

marginal zone B-cell lymphoma of nodal type

A primary (non-Hodgkin) nodal lymphoma with features identical to MALT lymphoma, without extranodal disease; monocytoid B cells may be prominent. The diagnosis of marginal zone B-cell lymphoma should not be made in patients with confirmed MALT lymphoma at other sites, Sjögren syndrome, or when another low-grade B-cell lymphoma (follicular, mantle cell) is present in the same node.

Occurrence
1.5% of NHL older adults.
 
Median age
60 years; F>M (60%).

Presenting features
Peripheral and abdominal lymph nodes (71% Stage 3/4), 30% bone marrow.
 
Outcome
60% overall survival at 5 years; 28% failure-free survival at 5 years.

“MALT”-type
Associated with prior or subsequent extranodal lymphoma in 44%; nodal involvement by MALT lymphoma.

Types of marginal zone B-cell lymphoma
• Splenic marginal zone lymphoma.
• Extranodal marginal zone B cell lymphoma (MALT lymphoma, or "mucosa-associated lymphoid tissue").
• Nodal marginal zone B cell lymphoma (NMZL).

All three are CD5 and CD10 negative

MALT pattern
80% of cases, parafollicular, perisinusoidal, interfollicular; reactive GC, preserved mantle zone.
 
Cytology
Monocytoid, irregular nuclei, rare admixed blast cells, frequent plasmacytoid differentiation, admixed neutrophils.
 
Splenic pattern
20% of cases vaguely nodular, regressed or reactive GC, absent mantle zone, expanded marginal zone poorly defined.
 
Cytology
Small to medium cells, pale cytoplasm, blasts with nucleoli; plasma cells in some cases.

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