Test

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:Typical HLL morphology, these medium sized cells have a distinctive "partly open" chromatin in an oval or bean-shaped nucleus, cytoplasm is blue/grey with typical hairy projections

Background to flow cytometric diagnosis

HCL expresses typical and unusual markers that together with morphology can allow diagnosed with some confidence using flow cytometry.

However, no marker is unique to HCL and unusual marker patterns can lead to diagnostic difficulty. If this is the case then the atypical features should be reported, since histopathology and molecular testing can each be used to further evaluate these cases.

Immunophenotype of CLL
Major markers useful in CLL diagnosis
Marker	Freq	Level	Comment
κ/λ		Stg	Expect strong restricted expression of κ or λ
FMC7		Stg	Typically this marker is strongly expressed
CD5		-	Infrequent but reported in some cases
CD10		-	Infrequently expressed in typica; CLL
CD11C		Stg	Strong expression of CD11c is typical of HCL
CD19		-	Expression is expected and may be strong in HCL
CD20		wk	Expression is expected, but characteristically weak
CD23		-	Characteristic of CLL, although can rarely be weak or absent
CD25		wk	Expressed by many cases of CLL but characteristically weak
CD38		wk	Expressed by some cases of CLL, typically weak
CD43		-	Similar to CD200, may be helpful in some cases
CD79b		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 positive in CLL and 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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