Although the word haematology implies a specialty that deals with diseases of the blood, the remit of the discipline encompasses the bone marrow and primary diseases of the lymph nodes and the spleen. Various entities fall within the province of the haematologist.

Much of the background to haematology is found in the topics of general pathology.

Full Blood Count

The full blood count is one the fundamental blood tests in many spheres of medicine and is integral to haematology. A full array of data from a full blood count incorporates many parameters but the most important items are the following.

Haemoglobin The concentration of haemoglobin in the blood
(Males 13-18g/dL; females 11.5-15.5g/dL)
White cell count Concentration of all white cells in the blood (4-11 x109 cells / L)
Separate results are also given for neutrophils, eosinophils, basophils, monocytes and lymphocytes
Platelet count The concentration of platelets in the blood (150-450 x109 platelets / L)
Mean corpuscular haemoglobin concentration (MCHC) The average concentration of haemoglobin in each red cell (32-36g/dL)
Mean cell volume (MCV) The average volume of an erythrocyte (75-95fL)

Bone Marrow Trephine

In some haematological diseases it is necessary to examine a sample of the haematopoietic bone marrow. This is usually obtained from the iliac crest, although the sternum is sometimes employed instead. The full trephine produces the trephine itself, which is a core of bone that is suitable for histopathological examination and an aspirate, which is in effect a cytological preparation. The aspirate is typically reported by the haematologists. Most trephines are sent to the histopathology department but some haematologists prefer to report the trephine themselves.