Rare Leukaemias
B cell Prolymphocytic Leukaemia (B-PLL)
*** B-PLL has been removed as an entity in the WHO-HAEM5 2022 classification. These patients will fit best either in ‘Prolymphocytic Progression of CLL’ or ‘Splenic B-Cell Lymphoma/Leukaemia with prominent nucleoli’, depending on the individual case. I have not deleted this section yet as will take some time for these changes to filter through. ***
1% of lymphocytic leukaemias
Median age 60-70, M=F
High WBC, B Symptoms, Massive Splenomegaly
50% of patients thrombocytopenic / anaemic
Aggressive disease, median survival 3 years from diagnosis
Diagnosis
Film – Prolymphocytes must be >55% of lymphoid cells seen, usually >90%
Immunophenotype – CD19+, CD20+, CD22+, SmIg++, CD5+/-, CD23-, SOX11-, CD1-
Cytogenetics – 17p del in 50%, C-MYC, TP53 mutation
Treatment
Difficult, poor responses
FCR / R-Benda / Ibrutinib / Alemtuzumab
Chronic Eosinophilic Leukaemia (CEL)
See Eosinophilia
Chronic Neutrophilic Leukaemia (CNL)
Rare myeloproliferative neoplasm
Persistent neutrophilic leucocytosis & hepatosplenomegaly
Diagnosis
WBC >25 with >80% of cells being mature neutrophils/band forms
CSF3R mutation present in >60% of cases
Treatment
?Ruxolitinib – Phase 2 study in CNL and aCML. 66% response rate for CNL.
Hairy Cell Leukaemia (HCL)
Pure Erythroid Leukaemia
Extremely rare
Any age including childhood
Usually progression from MDS but can occur de novo
Median survival only 3 months
Diagnosis
BM aspirate - >80% of cells are erythroid, with >30% proerythroblasts and no significant myeloblast presence.
Treatment
As for AML
T cell Large Granular Lymphocytic Leukaemia (T-LGL)
See T & NK Neoplasms
T cell Prolymphocytic Leukaemia (T-PLL)
See T & NK Neoplasms