Test

Background

Typical CLL can be diagnosed with some confidence using flow cytometry.

However, individual markers may not be expressed in all cases - this can cause diagnostic difficulty particularly in distinguishing CLL from atypical cases of MCL or MZL. If this is the case then the atypical features should be reported, and the possibility of alternative diagnoses acknowledged.

Note also that cases with a low lymphocytosis (<1x10⁹) may represent monoclonal B-lymphocytosis with CLL phenotype (click here for more).

Immunophenotype of MCL
Major markers useful in CLL diagnosis
Marker	Freq	Level	Comment
κ/λ			Expect moderate or strong restricted κ or λ expression
FMC7		-	FMC7 is frequently expressed by typical MCL
CD5		-	Expression of CD5 is characteristic of MCL
CD10		-	Infrequently expressed, expression may suggest FL
CD11C			Expressed in some cases of MCL but not typical
CD19		-	Expression is expected, typically more strongly than in CLL
CD20		wk	Expression is expected, typically stronger than CLL
CD23		-	Typically not expressed by MCL, may rarely be expressed
CD25			Not typical of MCL, not generally strong as HCL
CD38		wk	Expression is expected in MCL but CD138 should be absent
CD43		-	Similar to CD200, may be helpful in some cases
CD79a		wk	Expression is expected, but characteristically weak
CD103		-	Not expressed by CLL, consider HCL if found
CD138		-	Predominantly expressed at plasma cell differentiation
CD200		-	Characteristically (though not always) negative in MCL

Key to table:

Markers most useful in initial diagnosis are underlined in blue text

Key to colour code for expression frequency Click for link

Key to expression strength code and use Click for link

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