Case 255 Elizabeth Courville, MD Robert Hasserjian, MD Massachusetts General Hospital Society for Hematopathology/European Association for Haematopathology Workshop October 24, 2013

Clinical History 79 year old man Low energy, poor appetite, nausea CBC: –WBC 11.7 x 10 9 /L, 25% monocytes –Hgb 11.3 g/dL, MCV 101 fl –Platelets 163 x 10 9 /L

Aspirate Differential Count: 30% myeloid precursors, 40% erythroid precursors, 2% lymphs, 10% monocytes, 1% eosinophils, 1% basophils, 13% blasts and promonocytes, 3% plasma cells * * *

First bone marrow specimen diagnosis: Chronic myelomonocytic leukemia-2 (CMML-2) Patient was treated supportively CBC WBC x 109/L 44% monocytes, 8% promonocytes, 18% blasts Hgb 7.6 g/dL Platelets 109 x 109/L Three months after initial presentation:

Aspirate Differential Count: 4% myeloid precursors, 16% erythroid precursors, 5% lymphs, 4% monocytes, 71% blasts and promonocytes, 3% plasma cells

Mutated NPM1 (239 bp) NPM1 WT (235 bp) Cytoplasmic NPM1 staining; AML specimen Cytoplasmic NPM1 staining; CMML-2 specimen Cytogenetic findings: 46 XY [20] FLT3-ITD, >335bp FLT3 WT (330 bp)

Second bone marrow specimen diagnosis: NPM1-mutated AML with myelodysplasia related changes (FLT3-ITD mutation also present)

Second bone marrow specimen diagnosis: NPM1-mutated AML with myelodysplasia related changes AML-MRC defined by: Previous history of a myelodysplastic syndrome or myelodysplastic/myeloproliferative neoplasm Myelodysplastic syndrome-related cytogenetic abnormality Multilineage dysplasia Represent approximately 1/3 of all cases of AML Generally has a poor prognosis

Second bone marrow specimen diagnosis: NPM1-mutated AML with myelodysplasia related changes AML with mutated NPM1 NPM1 mutation occurs in ≈ 30% of adult AML and in ≈ 50% of adult AML with a normal karyotype. Usually associated with normal karyotype; although chromosomal aberrations are present 5-15% of the time. When they are present, cytogenetic aberrations do not appear to confer an adverse prognosis. (Haferlach, et al. Blood. 2009; 114: ) 40% also carry a FLT3-ITD. Favorable prognosis in the absence of a FLT3-ITD mutation. Coexistence of a FLT3-ITD mutation: adversely affects prognosis Multilineage dysplasia in AML with mutated NPM1: does not appear to confer an adverse prognosis (Falini, et al. Blood. 2010; 115: ).

318 pts with AML with de novo cytoplasmic/mutated NPM1. Myelodysplasia, as defined by 2008 WHO criteria, was detected in 23.3% of cases. Gene expression profiling of a subset of the cases revealed separation based on NPM1 status but not the presence or absence of dysplasia. No significant difference in overall survival or event free survival was observed between NPM1-mutated AML with and without multilineage dysplasia.

Second bone marrow specimen diagnosis: NPM1-mutated AML with myelodysplasia related changes AML with mutated NPM1 Usually occur as de novo cases without therapy related disease or a history of any antecedent myeloid neoplasm. (Falini, et al. Blood. 2007; 109: ). One study (Schnittger S et al. Leukemia 2011; 25: ), identified an NPM1 mutation in 37/283 (13.1%) of patients at diagnosis of secondary-AML following MDS or CMML.

NPM1 mutations in MDS prior to development of AML Modified from Schnittger S et al. Leukemia 2011; 25: NPM1 + -

NPM1 mutations are uncommon in CMML NPM1+ (%) NPM1+ (#) Gelsi-Boyer, et al. Br J Haematol. 2010;151: /53 Itzykson, et al. J Clin Oncol. 2013; 31: /260 Caudill, et al. Br J Haematol.2006;133; /60 Courville, et al. Modern Pathology. 2013;26: /44 Ernst, et al. Haematologica ; 95 : /97 Bains, et al. Am J Clin Pathol. 2011;135: /15

The few NPM1 positive CMML cases exhibit aggressive behavior NPM1+ (%) NPM1+ (#) Progressed to AML within 1 year Gelsi-Boyer, et al. Br J Haematol. 2010;151: /53N/A Itzykson, et al. J Clin Oncol. 2013; 31: /260ND Caudill, et al. Br J Haematol.2006;133; /603/3 Courville, et al. Modern Pathology. 2013;26: /442/2 Ernst, et al. Haematologica ; 95 : /97ND (poor overall survival) Bains, et al. Am J Clin Pathol. 2011;135: /151/2

Should NPM1-mutated CMML be considered an early de novo NPM1-mutated AML? –Screening of newly diagnosed cases of CMML for the NPM1 mutation may be warranted, with close clinical follow-up of positive cases.

Patient Follow-up The patient relapsed after induction chemotherapy and died 12 months after his AML diagnosis.