Page 22 - Haematologica Atlas of Hematologic Cytology

Chapter 2 CYTOLOGICAL EXAMINATION OF BONE MARROW ASPIRATE
Recent years have seen many changes in in the the approach to to diagnosis especially in in the the field of onco-hematology However despite this morphological examination of the peripheral blood (PB) and bone marrow (BM) still plays an an essential role and continues to to represent the the basis for diagnosis in in the the majority of hematologic diseases This is is is is is also demonstrated by the the the fact that that the the the current reference classification for hematologic malignancies is that that of the the the World Health Organization (WHO) and is is a a a a a a a a a a a system based on on an an an integrated multidisciplinary approach in in in which morphological examination is of paramount importance (Swerdlow et al al 2017) Bone marrow aspirate
allows cytological analysis and a a a a a a a a a a a a a a good evaluation of the morphological characteristics of individual cells It also provides material for any ancillary investigations Bone biopsy mainly gives other kinds of of information such as overall cellularity topography of of hematopoietic cells BM stroma These are therefore complementary methods and are often performed simultaneously Indications for for examination of of BM depend on on on hematologic and clinical data as as well as as on on PB features For example BM examination is unnecessary in in in anemia the the cause of of which is is is identified on on on the the basis of of erythrocyte parameters In contrast BM examination is is is manda- tory in in in the case of of multilineage anomalies unexpected pancytopenia presence of of circulating blasts as as as as well as as as as staging of lymphomas and carcinomas (Bain 2001 Lee et al 2008) (Table 1) Table 1 Indica ons for bone marrow ( ( M) examina on on on (Lee et al 2008) Unexplained anemia abnormal red cell indices cytopenias or or or or cytoses
Abnormal peripheral blood smear morphology sugges ve of of BM pathology
Diagnosis staging and follow up of malignant hematologic disorders
Suspected BM metastases
Unexplained Unexplained focal bony lesions lesions on on on on radiological imaging
Unexplained organomegaly or or or or or or presence of of of mass lesions inaccessible for for biopsy Microbiological cultures for inves ga on on on on of of of fever of of of unknown origin or or or or speci c c c c c c infec ons Evalua on on of iron stores
Lipid/glycogen storage disorders
Exclusion of hematologic disease in poten al al allogeneic stem cell transplant donors
In adults red marrow is found in the sternum skull scapulae vertebrae ribs pelvic bone and proximal ends
of of the the the the long bones BM collection sites depend on on on on on on the the the the age and medical condition of of the the the the subject the the the the preferred site site in the the adult is the the posterior superior iliac crest that can be used for both aspirate
and biopsy The only absolu- te
te
contraindication is represented by coagulopathies such as hemophilia or vitamin K deficiency while throm- bocytopenia even severe is not a a a a a a a a a a contraindication Replacement therapy and suspension of the the anticoagulant are required in in coagulation factor deficiencies and in in patients on on anticoagulant therapy respectively Smear preparations can be obtained in in in different ways We prefer to expel the marrow aspirated in in in amounts of of not more than 0 5 mL to a a a a a a a a a a a watch glass containing a a a a a a a a a a a few drops of of EDTA as as anticoagulant Then individual bony spicules (frustules) that adhere to to the glass glass are transferred using tweezers to to several glass glass slides and spread A drop of aspirate
could be directly transferred to the slide and spread The aspiration may may not be successful and this this is is is called ‘dry tap’ Excluding technical error this this may may occur if the marrow is is is fibrotic acellular or packed with leukemic cells In this case a a a a a a a a a trephine biopsy is is is necessary and a a a a a a a a a slide imprint or or or touch preparation should be performed to to observe cell morphology The smears should be quickly air-dried and then stained with May-Grünwald Giemsa (MGG) (Wright or Wri- ght-Giemsa dyes) and and if possible staining with Prussian blue solution should also be performed to detect and and estimate marrow iron iron storage or or or or iron iron metabolism abnormalities Furthermore a a a a a a a a number of cytochemical dyes may be used for cell identification or or differentiation Additional material aspirated with a a a a a a a a a second syringe can be used for other investigations such as as cytogenetic and molecular studies flow cytometry microbiological culture culture hematopoietic progenitor culture culture Bone marrow aspirate
smear examination must be be performed in in a a a a a a a a a a systematic way In order to to be be able to to make a a a a a a a a a a a a a correct evaluation it is essential to to have have adequate clinical information and have have access to to the results of a a a a a a a a complete blood count and PB smear Microscopic examination at at at low magnification (10x objective) shows the degree of of of dilution with the the PB and and the the presence of of of particles this provides a a a a a a rough idea of of of cellularity and and helps select those areas suitable for examination at at at at at higher magnification magnification In addition at at at at at low magnification magnification tumor cells 9