Bone Marrow Studies

BONE MARROW STUDIES The Bone Marrow -

Occupies 3.4% to 5.9% of TBW(1600-3700 g) At birth, all bones contain the hematopoietic (red) marrow 5th / 7th year: yellow marrow begin to replace the red marrow in the long bones of extremities

Sites of collection -

ADULTS: anterior iliac crest, **superior iliac crest, ribs & vertebrae CHILDREN < 1 y/o: anteromedial surface of tibia

BM Aspiration and Biopsy -

2 parts of the BM sample o Aspirate: useful for cytologic type & proportions of hematopoietic cells in the blood. o Core biopsy Specimen: - determine cellularity & the anatomic relationship of cells to fat and CT stroma: important for determining/evaluating diseases that characteristically produce focal lesions; also allows evaluation of bone spicules. - used to confirm aplastic anemia * dry tap – unable to aspirate BM cell during aspiration of BM

Indications of marrow exam -

Not required for cases of anemia: etiology is apparent by the RBC indices and other laboratory tests. Multilineage abnormalities in the PB Circulating blasts (except in NB or infants w/ infection) Pancytopenic patients (except those who are receiving BM-suppressive therapy) Staging/grading purpose in Hodgkin lymphoma and carcinoma. *Should only be performed where it is essential fro diagnosis or patient management.

Bone Marrow Procedures -

Needles : Jamshidi, Westerman-Jensen, Snarecoil o Possible to obtain a core of a bone and its enclosed marrow o 25 gauge –replaced by 21 gauge 10-20mL syringe (1 to 2 cc) Position: right or left lateral decubitus Universal precaution o Anaesthetic solution: 1% or 2% lidocaine or procaine (create a papule using a 25 gauge needle)

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o Draped 2mL anaesthetic solution Incision (3mm, No. 11 scalpel) Aspirated particles: syringe to glass cover slips washed w/ 70% ethanol Second coverslip: pull aprt/ slides Wright – Giemsa Stain Marrow core: touch preparation fixed w/ Zenker’s solution, 5% glacial acetic solution – buffered solution

Aspirates -

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LPO o OIO o o o

Detect the presence of bone spicules (intact marrow consisting of the hematopoietic and stromal elements of the BM) Hematopoietic cells Count 300 to 500 nucleated RC to obtain a reliable differentaial count to determine the M:E ratio 1.5:1 – 3.3:1 (mean: 2.3: 1)

Note : myelocyte, metamyelocyte, monocyte, megakaryocytes Cellularity

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Estimated by observing the proportion of cells to empty fat vacuoles Relative cellularity