478

STERNAL MARROW BIOPSYBY E. NEUMARK, M.B., B.S.(Lond.)

Lecturer in Pathology, St. Mary's Hospital Medical School, London

Sternal puncture has become established as auseful diagnostic aid since its introduction byArinkin (1929) just 20 years ago. The bonemarrow in the sternum remains haemopoieticallyactive until late in life and during regenerationshows increased activity more readily than manyother bones.To perform sternal puncture an area of skin at

the level of the second or third intercostal space,just to one side of the midline, is anaesthetizedand through it the periosteum is infiltrated. The

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FIG. x.-Sternal puncture needle. Klima's pattern,modified by Britton.

puncture needle (Fig. i) is pushed through theskin and its guard fixed 0.5 cm. above the skinlevel. The cortex of the sternum is pierced slightlyobliquely by gentle rotatory movements, while thepatient holds his breath in inspiration for a fewseconds. A sudden give is felt when the spongy bonemarrow is reached. 'A well-fitting 5 ml. syringewhich has been rinsed in saline is attached to the

needle and about 0.3 ml. of fluid is aspirated. Thepatient experiences a short, sharp pain whensuction is made. The marrow material is placedin a watch glass and smears are made at once anddried by waving them rapidly. If desired the totalnucleated cell content is estimated by the methodused for counting leucocytes. The remainingspecimen is allowed to clot, fixed in Helly's fluid,sectioned and stained like' a histological preparation.Macroscopic examination of the material shouldnot be neglected. An increase of fat globules mayindicate aplastic or hypoplastic conditions, and anincrease of little greyish marrow fragments occursin hyperplasia. The smears are stained withLeishman's or other similar stains and examinedmicroscopically. Megakaryocytes are usuallyeasily identified with the low power lens, and con-firm that the material obtained is in fact bonemarrow. The marrow smears are carefully studiedwith the immersion lens and at'least 500 cells arecounted and classified. The normal figures forsternal marrow counts (Whitby and Britton, 1946)are shown in Table i.

TABLE I

Normal MyelogramMyeloid cells:

Neutrophil polymorphs .. .. 20-50 per cent.Eosinophil polymorphs .. .. -4Neutrophil metamyelocytes .. 2.5-12Eosinophil metamyeloiytes .. 0-2.5Neutrophil myelocytes .. .. 2-8 ',,Eosinophil myelocytes .. .. 0-3Basophils .. .. .. .. -I ,Promyelocytes .. .. .. 0.5-5Myeloblasts -.. .. .. of. 5

Erythroid cells:Late (orthochromatic) normoblasts 7-i9Early (basophilic) and intermediate

(polychromatic) normoblasts .. 4-S ,Proerythroblasts .. .. ..Haemocytoblasts .. .. .. 0-I

Other cells:Lymphocytes .. .. .. 5-20Monocytes .. .. .. .. ,-5Plasma cells .. .. .. 0-IMegakaryocytes .. .. .. o.2-i

Myeloid-erythroid ratio 8: i-2: I

October I949 NEUMARK: Sternal Marrow Biopsy 479

'TABLE 2

ORICIN OF BlOOD CELLS

Reticulo-endothelial System in Bone Marrow, Spleen. Lymph Glands, etc

Haermocytoblast

Primitive White Blood Cell

blast Proerythroblast Mega aryoblastMyeloblast

Lvel of Promyelocy e

MoscBasophilic Early

Activity Neutrophil Eosinophil Basophil Proplasmocyte Normoblast Megaloblast PromegakaryocyteMyel cyte Myelocyte Myelocyte Promonocyte

PolychromatEc IntermediateNeutrophil Eosinophil Basophil Normoblast Megaloblast Megakaryocyte

Metamyelocyte Menamylocyte Metamyl ocyte

Orsocromatic LaeNeutrophil - - - -- Normoblast Megal last -stacell~

stahcell- -ReticulocyteCells

found in

Peripheral NeaUrophil Eosinophil Mast cell Monocyte Plasma cell Large Lymphocyte

Elood Polymorphonuclear Leucocytes

Macropolycyte Small Lymphocyte Erythrocyte Megalocvte Platelets

The development of cells is shown diagram-matically in Table 2, but it should be rememb redthat megaloblasts are not normally seen in themarrow, and megalocytes do not normally occurin the blood. Their morphology can be studiedin the more detailed books, such as the monographby Leit-ner (I949). Mitotic figures can be readilystudied in sternal marrow preparations and inmany instances provide useful information inassessing disorders of the haemopoietic organs,their activity, severity and prognosis.

In the untreated case of pernicious anaemia themarrow is characterized by megaloblastic hyper-plasia, but the myeloid cells and the megakaryo-cytes also show certain changes, such as largecell forms. Treatment with liver should not becommenced until a definite diagnosis is reached.Following the administration of liver in adequateamounts the megaloblastic marrow becomestransformed into normoblastic marrow, often asrapidly as in 6 to I2 hours. Sprue, perniciousanaemia of pregnancy, tropical megalocyticanaemia and achrestic anaemia show marrowpictures similar to classical pernicious anaemia.Megaloblasts such as described by Turnbull(1936) are only seen in pernicious and alliedanaemias (Figs. 2 and 3).

Idiopathic hypochromic anaemia, the haemor-rhagic anaemias and most secondary anaemiasshow normoblastic hyperplasia of the erythro-poietic marrow portion. Certain other symp-tomatic anaemias, such as in nephritis, severe in-fections, benzol poisoning and in malignantdisease, may show hypoplasia and in such casesthe prognosis is less favourable, but the normo-blasts may increase in response to treatment. Inaplastic anaemia, myelosclerosis, and similar con-ditions the total number of marrow cells is muchreduced, and therefore the percentage of lympho-cytes may be increased, though their absolutefigure is not altered.

In the haemolytic anaemias, such as haemolyticicterus, Cooley's anaemia and in toxic haemolyticstates, the increase of erythroblasts is particularlymarked and extreme marrow hyperplasia maycause skeletal changes. Polycythaemia rubra veraaffects all three marrow systems (red, white andmegakaryocytic) by hyperplasia, but in erythro-cytosis only the normoblasts are increased.Erythraemic myelosis (di Guglielmo's disease) ischaracterized by enormous pathological erythro-blastic hyperplasia and suppression of the myeloidand megakaryocytic series of cells.

In chronic myeloid leukaemia, sternal marrow

480 POST GRADUATE MEDICAL JOURNAL October 1949

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FIG. 2.-Megloblasts, normoblasts and giant myelo-cytes. The early megaloblast near the polymorphshows the typical fine chromatin structure. Froman untreated case of pernicious anaemia (Leishman,x Io000).

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FIG. 3.-An early megaloblast with pseudopodia of thecytoplasm and abnormal mitosis of the nucleus.From a case of pernicious anaemia in relapse(Leishman, x 6oo).

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FIG. 4.-Neutrophil polymorphs, myelocytes, pro-myelocytes and a megakaryocyte. From a case ofchronic myeloid leukaemia (Leishman, x iooo).

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FIG. 5.-Myeloblasts, one of them in mitosis, with littlecytoplasm and nucleoli in the nucleus. From acase of acute myeloid leukaemia and chloroma(Leishman, x :,ooo).

October I949 NEUMARK: Sternal Marrow Biopsy 48i

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FIC. 6.-Large primitive plasma cells with basophilic cytoplasm, some with cartwheelpattern of the nucleus. From a case of multiple myelcmatosis (Leishman, x 400).

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FIG. 7.-Megakaryocytes in various stages of matura-tion, those with pleomorphic nuclei formingplatelets. From a case of idiopathic thrombo-cytopenic purpura (Leishman, x 500).

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FIG. 8.-Sternal trephine. Infiltration of bone marrowby lymphoid cells while megakaryocytes remain.From a case of lymphatic leukaemia (I-faematoxylinand eosin, x 235).

482 POST GRADUATE MEDICAL JOURNAL October Ij949

biopsy produces a picture similar to that found inthe peripheral blood, but it is in the cases withoutleucocytosis that sternal puncture is of diagnosticimportance (Figs. 4 and 5). Lymphatic leukaemiadoes not affect the bone marrow primarily andtherefore in early cases a characteristic myelogramcannot always be expected. Once the bone marrowis infiltrated (Fig. 6) the number of lymphocytesand immature lymphoid cells in the marrow ismuch increased. In acute leukaemia the distinc-tion between myeloid and lymphatic leukaemia isoften impossible, even with the help of marrowbiopsy; some cases show myeloblasts with lobednuclei (' paramyeloblasts ' of Naegeli's ter-minology) which simulate monocytes. In themarrow as well as in the blood these active cellsindicate a rapidly progressive disease and herald afatal prognosis. Mutiple myelomatosis in themajority of cases is easily diagnosed by sternalpuncture. The plasma cells or their precursorsare unusually numerous, sometimes almost to theexclusion of other cells (Fig. 6).

Sternal marrow biopsy is particularly valuablein the accurate diagnosis and assessment ofprognosis in cases of agranulocytosis, aplasticanaemia and other marrow aplasias. In themajority of cases there is maturation arrest with anormal number of early cells and a decrease ofpolymorphs and late normoblasts only. In suchcases recovery may be expected, but when thereis aphasia or severe hypoplasia of the myeloid orerythroid series the prognosis must be guarded.Sometimes the true nature of the pathologicalprocess can only be revealed by repeated sternalpunctures or a sternal trephine.Some case of glandular fever show a peripheral

blood picture which simulates leukaemia. Theabsence of the atypical cells from the marrow willhelp when the differential diagnosis is difficult andwill exclude leukaemia.

In deciding whether or not a case of thrombo-cytopenic purpura will benefit from splenectomysternal puncture is particularly valuable. Whenthe megakaryocytes and their precursors are scantyor absent, splenectomy will rarely be followed by a

cure, but when the non-platelet-forming pro-megakaryocytes are abundant, splenectomy fre-quently results in a removal of the inhibition ofmaturation (Fig. 7).

Occasionally malignant disease may be diag-nosed by the finding of clusters of cells in themarrow, but these cases are, of course, those withskeletal metastases and such advanced stages maybe diagnosed or suspected by the appearance ofimmature red and white cells in the peripheralblood, i.e. leuco-erythroblastic anaemia. InHodgkin's disease, late cases may show the typicalmirror-image giant cells, usually associated withthe names of Dorothy Reed and Sternberg. Forthe detection of malarial parasites, leishmania ormicrofilariae sternal puncture is better than splenicpuncture because it is much safer.

Sternal puncture has been used for blood trans-fusion, infusions and the injection of therapeuticpreparations, but such a procedure is difficult andoften hazardous. Intramedullary infusions canonly be given very slowly and they are thereforeuseless in an emergency.A thorough general search of marrow smears,

the differential count of marrow cells in severalstained preparations and the interpretation of theresults obtained is a laborious process and usuallyoccupies even a skilled worker for at least twohours. It rewards him with a thorough training incytology and a variety of sometimes very beautifulmorphological pictures, especially when mitoticfigures are studied.

Fig. 6 is included by courtesy of the Editor,St. Mary's Hospital Gazette. The other photo-micrographs are by W. Pereira.

BIBLIOGRAPHY

ARINKIN, M. I. (1929), Folia haemat., Lpz., 38, 233.LEITNER, S. J. (1949), 'Bone Marrow Biopsy; Haematology in

the Light of Sternal Puncture.' English translation, revised andedited by C. J. C. Britton and E. Neumark, J. and A. Churchill,London.

TURNBULL, H. M. (1936), in Vaughan, J. M. (1936), 'TheAnaemias,' second edition, Oxford Medical Publications,London.

WHITBY, L. E. H., and BRITTON, C. J. C. (1946), ' Disorders ofthe Blood,' fifth edition, J. and A. Churchill, London.