Differential diagnosis between HCL and HCL-like neoplasms (SMZL, HCL-v, SDRPBCL)
| Features . | HCL . | SMZL . | HCL-v . | SDRPBCL . |
|---|---|---|---|---|
| Morphology | ||||
| Nucleus* | Oval, sometimes “coffee bean” shaped | Round | Round/oval | Round/oval, sometimes eccentric |
| Nucleolus* | Absent | Absent or small | Clearly evident | Absent or small |
| Cytoplasm* | Abundant, pale | Moderately abundant, basophil, sometimes with plasmacytoid features | Abundant | Moderately abundant, basophil, sometimes with plasmacytoid features |
| Cell surface | Thin, often long projections distributed all over the surface (circumferential) | Projections with a polar (noncircumferential) distribution | Similar to HCL | Short and thick projections with polar distribution |
| BM infiltration pattern | Diffuse and/or interstitial | Nodular and/or intrasinusoidal | Diffuse, intrasinusoidal, and/or interstitial | Intrasinusoidal, interstitial, and/or nodular |
| Splenic infiltration pattern | Red pulp, with effacement of white pulp | White pulp | Red pulp | Diffuse (red and white pulp) |
| Immunophenotype and genetic lesions | ||||
| Immunophenotypic markers | CD20+, CD5−, CD10−, CD23−CD103+, CD25+, CD11c+, CD123+, AnnexinA1+, BRAF V600E+ | CD20+, CD5−, CD10−, CD23−CD103−/+, CD25−/+, CD11c+/, CD123−, AnnexinA1−, BRAF V600E− | CD20+, CD5−, CD10−, CD23−CD103+, CD25−, CD11c+, CD123−, AnnexinA1−, BRAF V600E− | CD20+, CD5−/+, CD10−, CD23−/+,CD103−/+, CD25−, CD11c+, CD123−, AnnexinA1−, BRAF V600E− |
| Genetic lesions | BRAF V600E mutation in >97% of cases; KLF2 and CDKN1B mutations each in 16% of cases | Del(7q) in ∼30% of cases, NOTCH2 mutations in 10%-25% of cases, NF-κB pathway mutations in ∼35% of cases, KLF2 mutations in 20%-40% of cases | MAP2K1 mutations in 50% of cases; 17p (TP53) deletion in ∼30% of cases | Not well characterized |
| Features . | HCL . | SMZL . | HCL-v . | SDRPBCL . |
|---|---|---|---|---|
| Morphology | ||||
| Nucleus* | Oval, sometimes “coffee bean” shaped | Round | Round/oval | Round/oval, sometimes eccentric |
| Nucleolus* | Absent | Absent or small | Clearly evident | Absent or small |
| Cytoplasm* | Abundant, pale | Moderately abundant, basophil, sometimes with plasmacytoid features | Abundant | Moderately abundant, basophil, sometimes with plasmacytoid features |
| Cell surface | Thin, often long projections distributed all over the surface (circumferential) | Projections with a polar (noncircumferential) distribution | Similar to HCL | Short and thick projections with polar distribution |
| BM infiltration pattern | Diffuse and/or interstitial | Nodular and/or intrasinusoidal | Diffuse, intrasinusoidal, and/or interstitial | Intrasinusoidal, interstitial, and/or nodular |
| Splenic infiltration pattern | Red pulp, with effacement of white pulp | White pulp | Red pulp | Diffuse (red and white pulp) |
| Immunophenotype and genetic lesions | ||||
| Immunophenotypic markers | CD20+, CD5−, CD10−, CD23−CD103+, CD25+, CD11c+, CD123+, AnnexinA1+, BRAF V600E+ | CD20+, CD5−, CD10−, CD23−CD103−/+, CD25−/+, CD11c+/, CD123−, AnnexinA1−, BRAF V600E− | CD20+, CD5−, CD10−, CD23−CD103+, CD25−, CD11c+, CD123−, AnnexinA1−, BRAF V600E− | CD20+, CD5−/+, CD10−, CD23−/+,CD103−/+, CD25−, CD11c+, CD123−, AnnexinA1−, BRAF V600E− |
| Genetic lesions | BRAF V600E mutation in >97% of cases; KLF2 and CDKN1B mutations each in 16% of cases | Del(7q) in ∼30% of cases, NOTCH2 mutations in 10%-25% of cases, NF-κB pathway mutations in ∼35% of cases, KLF2 mutations in 20%-40% of cases | MAP2K1 mutations in 50% of cases; 17p (TP53) deletion in ∼30% of cases | Not well characterized |
In smears stained according to May-Grünwald Giemsa.