A Colour Atlas of Haematological Cytology

F.G.J. Hayhoe, R.J. Flemans

• Editore: CRC Press
• Anno: 2020
• ISBN:
  9781000725575
• Edizione: 2
• Argomento: Medicina
• Categoria: Ematologia

The second edition of this atlas has been revised and greatly en-larged to take account of recent diagnostic advances in the field of haematology. It contains 750 color photomicrographs of common and less common cell types, and is intended to supplement the per-sonal study of preparations under the microscope.The photographs are grouped into five sections covering red cells and their precursors; nonerythroid cells of myeloid origin; lympho-cytes, plasma cells and their derivatives and precursors; miscella-neous cells of blood and marrow, including foreign cells and para-sites; and the imprint cytology of lymph nodes and spleen. Each section is preceded by a brief introduction, and an appendix pro-vides technical details of staining methods. The text accompanying the illustrations serves chiefly to identify the cells, but also gives explanations of certain unusual appearances and the cytochemical reactions where necessary.A Colour Atlas of Haematological Cytology will be useful to students of medicine and medical laboratory science, as well as to doctors and technicians specializing in the diagnosis of haematological disease.

Part 1
The red cells and their precursors

The nomenclature of red cell precursors is confusing. The earliest recognisable member of the red cell series, the proerythroblast, has the cytoplasmic basophilia, the nucleolated and moderately leptochromatic nucleus and the large cell size generally characteristic of primitive cells. It gives rise to a sequence of nucleated cells, the erythroblasts, which progressively develop increasingly pachychromatic nuclei, lose their nucleoli and their cytoplasmic basophilia and acquire a rising haemoglobin content. This sequence is subject to an arbitrary division into stages, the commonest division being into three:

• (1) The basophilic or early erythroblast, or normo-blast A
• (2) The polychromatic or intermediate erythroblast, or normoblast B
• (3) The orthochromatic or late erythroblast, or normoblast, or normoblast C.

There are objections to the use of many of these terms, but they are all so firmly entrenched in common usage that they must be accepted. When authors use different or more elaborate staging and nomenclature they usually define their terminology, but those who use any of the synonyms above expect them to be understood without further explanation.

The proerythroblast is not itself the functional stem cell serving as a self-maintaining progenitor of the normoblast series, but is derived from an earlier functional myeloid stem cell of unidentified morphology having pluripotential capacity for giving rise to cells of erythroid, granulocytic, monocytic and megakaryocyte-platelet lines.

Kinetic studies with radio-isotopically labelled cells suggest that four cell cycles culminating in mitoses occur during development from proerythroblast to late normo-blast, three at the proerythroblast and early basophilic normoblast stages, and the last at the polychromatic intermediate normoblast stage. Nests of erythroblasts of different stages of maturity commonly occur in apposition around a centrally situated reticulo-endothelial cell. Transfer of iron may be effected in one or other direction, and the central macrophage is often rich in stainable free iron. Late normoblasts do not undergo a further cell cycle but lose their nuclei by extrusion and give rise to marrow reticulocytes.

Reticulocytes spend up to two days in the bone-marrow before being released into the peripheral blood. There they make up normally less than 1 per cent of the red cell population and within another one to two days lose the remnants of cytoplasmic basophilia which give them their characteristic staining properties, and become orthochromatic mature red cells.

Mature red cells survive some 120 days before destruction. They are normally circular and fairly uniform in diameter, but are readily distorted by external pressure, as from neighbouring cells in a smear. Their structure as biconcave discs leads to weaker eosinophil staining at the centre than at the periphery, a feature which is least prominent at the tail of a blood smear where the cells are most spread out and flattened. In the body of the smear it becomes more conspicuo...