Morfologia normale e patologica

Transcription

1 Morfologia normale e patologica Gina Zini Centro di Ricerca ReCAMH Dpt. Ematologia Università Cattolica S. Cuore - Roma EMATOLOGIA DI LABORATORIO: percorsi diagnostici e obiettivi clinici. Milano Novembre

2 Prerequisites for classification of myeloid neoplasms by WHO 2008 criteria (I) Morphologic, cytochemical and immunophenotypic features of the neoplastic cell -toestablish lineage and degree of maturation - to decide whether cellular proliferation is cytologically normal or dysplastic, effective or ineffective Criteria should be applied to initial specimens prior to any therapy including GFs

3 Prerequisites for classification of myeloid neoplasms by WHO 2008 criteria (II) Blast percentage on PB and BM remains fundamental for categorizing and for evaluating disease progression Cytogenetic and molecular genetic are required at diagnosis - to identify specific genetically defined entities - to establish a baseline to assess disease progression

4 Morphological quantitative rules (I) Peripheral Blood Manual differential on 200 cells, WBC RBC and Plt qualitative evaluation,? Neutrophil granularity? Well controlled staining Bone Marrow aspirate Manual differential on 500 nucleated cells guidelines (undiluted samples, areas close to particles, multiple smears) Cell count includes: - blasts and promonocytes - promyelocytes, myelocytes, metamyelocyes, band neutrophils, segmented neutrophils - eosinophils, basophils, monocytes, mast cells - lymphocytes - erythroid precursors Megakaryocytes are not included

5 BMF cell count: PB diluition effects on cell count at different volumes Dresch et al. J Clin Pathol 1974.

6 particles? Y acceptable quality? Y cellularity? N N MGKs or other precursors? Y BMF highly reduced increased, normal or slightly reduced N PB qualitative evaluation (blasts,dysplasia, cancer cells ) quantitative (myelogram) and qualitative evaluation

7

8 Morphological quantitative rules (II) From the FAB 1976 to the WHO 2008 the blast percentage remains a major factor in diagnosis, subclassification and prognosis The definition of a blast cell is still based on that one proposed in 1976 by the FAB group. It is unclear whether it has been applied in the same manner worldwide. Since the WHO has changed the definition of AML (minimum criterion is 20% blasts) and since RAEB has been diveded into 2 groups (5 to 9% and 10 to 19% of blasts, respectiely) it has become clear that the definition of blasts of granulocyte lineage should be more precise. Flow cytometry determination should not be used as substitute (diluition, not all blasts are CD34+)

9 Bl 20% Bl 20% Bl < 20%

10 Blasts ANC and NEC Myelogram 1 Myelogram 2 Myelogram 3 Granulocytic series 50% Blasts 20% Erythroid series 25% Lymphocytes 5% L/E= 2,8 Blasts/ ANC: 20% DGN: AML Granulocytic series 25% Blasts 5% Erythroid series 65% Lymphocytes 5% L/E= 0,46 Blasts /NEC: 5 x100/30= 16,6% DGN: AREB II Granulocytic series 10% Blasts 4% Erythroid series 80% Lymphocytes 6% L/E= 0,17 Blasts /NEC: 4 x100/14= 28,57% DGN: AML * ANC: all nucleated cells * NEC: non erythroid cells. Lymphocytes and plasmacells are excluded too

11 WHO 2008 Diagnostic algorythm

12

13 WHO 2008 MDS Classification - Adults

14 WHO 2008 MDS Classification - Childhood Simultaneous proliferation and apoptosis of hematopoietic cells Additional category: Refractory Cytopenia of Childhood (RCC) Children Usually hypocellular BM <2% blasts in PB <5% blasts in BM Persisten cytopenia(s) with dysplasia

15 WHO 2008: Acute Leukemia and Related Precursors Neoplasms

16 AML with myelodisplasia-related changes Dysplasiamustbepresentin at least 50% of the cells at least in 2 BM cell lines.

17 What is a Ring Sideroblast? An erythroblast with siderotic granules 5 or more [Juneja 1983] 10 or more [Cazzola 1988, Brunning (WHO) 2001] Covering a certain proportion of the nuclear outline A third or more [Juneja 1983, Cazzola 1988, Brunning 2001] What the 2008 WHO classification will advise 5 or more siderotic granules Covering a third or more of the nuclear circumference

18 WHO 2008: What is a Blast Cell? Myeloblasts, monoblasts and megacaryoblasts should be included. Erythroblats should be considered blast equivalent only in the Pure acute erythroid leukemia. Promonocytes are considered monoblast equivalent when the requisite percentage is tallied for the diagnosis of acute monoblastic, acute monocytic and acute myelomonocytic leukemia. In acute promyelocytic leukemia the blast equivalent is the abnormal promyelocyte. Small dysplastic MGK and micromgk are not blasts.

19 Myeloblasts

20