Marrow involvement | Interstitial, diffuse pattern (fried egg morphology) Marrow reticulin fibrosis | Sinusoidal may be interstitial | Nodular may be intrasinusoidal | Intrasinusoidal, may be interstitial or nodular |
Immunophenotype by flow cytometric analysis | CD11c+, CD19+, CD20+ bright, CD22+, CD25+, CD103+,CD123+, FMC7+, kappa or lambda (strong) | CD11c+, CD19+, CD20+, CD22+, CD27+, CD79b+, CD103+, FMC7+, kappa or lambda strong Negative for CD25–, CD123– | CD11c+, CD19+, CD20+, CD22+, CD27+, CD79b+, FMC7+, kappa or lambda strong Negative for CD25–, CD123– | CD11c+/–, CD103+/–, CD19+, CD20+, kappa or lambda+ Negative for CD25–, CD123– |
Immunophenotype by immunohistochemistry | DBA44+ Annexin A1+ Immuno-TRAP+ Cyclin D1+ Faint t-Bet+ V600E BRAF+ | DBA44+ Annexin A1– Immuno-TRAP– Cyclin D1– t-Bet– V600E BRAF– | DBA44+/– Annexin A1– Immuno-TRAP– Cyclin D1– t-Bet– V600E BRAF– | DBA44+ Annexin A1– Immuno-TRAP– Cyclin D1– t-Bet– V600E BRAF– |