Page 308 - Textbook of Pathology, 6th Edition

292 1. Pallor. Pallor is the most common and characteristic sign evaluated in an area where there is neither Rouleaux
which may be seen in the mucous membranes, conjunctivae formation nor so thin as to cause red cell distortion. Such an
and skin. area can usually be found at junction of the body with the
2. Cardiovascular system. A hyperdynamic circulation may tail of the film, but not actually at the tail. The following
be present with tachycardia, collapsing pulse, cardiomegaly, abnormalities in erythroid series of cells are particularly
midsystolic flow murmur, dyspnoea on exertion, and in the looked for in a blood smear:
case of elderly, congestive heart failure. 1. Variation in size (Anisocytosis). Normally, there is slight
3. Central nervous system. The older patients may develop variation in diameter of the red cells from 6.7-7.7 μm (mean
symptoms referable to the CNS such as attacks of faintness, value 7.2 μm). Increased variation in size of the red cell is
giddiness, headache, tinnitus, drowsiness, numbness and termed anisocytosis. Anisocytosis may be due to the presence
tingling sensations of the hands and feet. of cells larger than normal (macrocytosis) or cells smaller than
normal (microcytosis). Sometimes both microcytosis and
4. Ocular manifestations. Retinal haemorrhages may occur macrocytosis are present (dimorphic).
if there is associated vascular disease or bleeding diathesis.
Macrocytes are classically found in megaloblastic anaemia;
5. Reproductivesystem. Menstrual disturbances such as other causes are aplastic anaemia, other dyserythropoietic
amenorrhoea and menorrhagia and loss of libido are some anaemias, chronic liver disease and in conditions with
of the manifestations involving the reproductive system in increased erythropoiesis.
anaemic subjects. Microcytes are present in iron deficiency anaemia,
6. Renal system. Mild proteinuria and impaired concen- thalassaemia and spherocytosis. They may also result from
SECTION II
trating capacity of the kidney may occur in severe anaemia. fragmentation of erythrocytes such as in haemolytic anaemia.
7. Gastrointestinalsystem. Anorexia, flatulence, nausea, 2. Variation in shape (Poikilocytosis). Increased variation
constipation and weight loss may occur. in shape of the red cells is termed poikilocytosis. The nature
In addition to the general features, specific signs may be of the abnormal shape determines the cause of anaemia.
associated with particular types of anaemia which are Poikilocytes are produced in various types of abnormal
described later together with discussion of specific types of erythropoiesis e.g. in megaloblastic anaemia, iron deficiency
anaemias. anaemia, thalassaemia, myelosclerosis and microangiopathic
haemolytic anaemia.
Investigations of the Anaemic Subject 3. Inadequate haemoglobin formation (Hypochromasia).

After obtaining the full medical history pertaining to different Normally, the intensity of pink staining of haemoglobin in a
general and specific signs and symptoms, the patient is Romanowsky-stained blood smear gradually decreases from
examined for evidence of anaemia. Special emphasis is placed the periphery to the centre of the cell. Increased central pallor
on colour of the skin, conjunctivae, sclerae and nails. Changes is referred to as hypochromasia. It may develop either from
in the retina, atrophy of the papillae of the tongue, rectal lowered haemoglobin content (e.g. in iron deficiency
examination for evidence of bleeding, and presence of anaemia, chronic infections), or due to thinness of the red
hepatomegaly, splenomegaly, lymphadenopathy and bony cells (e.g. in thalassaemia, sideroblastic anaemia). Unusually
tenderness are looked for. deep pink staining of the red cells due to increased haemo-
In order to confirm or deny the presence of anaemia, its globin concentration is termed hyperchromasia and may be
type and its cause, the following plan of investigations is found in megaloblastic anaemia, spherocytosis and in
generally followed, of which complete blood counts (CBC) neonatal blood.
with reticulocyte count is the basic test. 4. Compensatory erythropoiesis. A number of changes are
Haematology and Lymphoreticular Tissues
associated with compensatory increase in erythropoietic
A. HAEMOGLOBIN ESTIMATION. The first and foremost activity. These are as under:
investigation in any suspected case of anaemia is to carry i) Polychromasia is defined as the red cells having more than
out a haemoglobin estimation. Several methods are available one type of colour. Polychromatic red cells are slightly larger,
but most reliable and accurate is the cyanmethaemoglobin generally stained bluish-grey and represent reticulocytes and,
(HiCN) method employing Drabkin’s solution and a thus, correlate well with reticulocyte count.
spectrophotometer. If the haemoglobin value is below the ii) Erythroblastaemia is the presence of nucleated red cells in
lower limit of the normal range for particular age and sex, the peripheral blood film. A small number of erythroblasts
the patient is said to be anaemic. In pregnancy, there is (or normoblasts) may be normally found in cord blood at
haemodilution and, therefore, the lower limit in normal birth. They are found in large numbers in haemolytic disease
pregnant women is less (10.5 g/dl) than in the non-pregnant of the newborn, other haemolytic disorders and in
state.
extramedullary erythropoiesis. They may also appear in the
B. PERIPHERAL BLOOD FILM EXAMINATION. The blood in various types of severe anaemias except in aplastic
haemoglobin estimation is invariably followed by anaemia. Erythroblastaemia may also occur after
examination of a peripheral blood film for morphologic splenectomy.
features after staining it with the Romanowsky dyes (e.g. iii) Punctate basophilia or basophilic stippling is diffuse and
Leishman’s stain, May-Grünwald-Giemsa’s stain, Jenner- uniform basophilic granularity in the cell which does not
Giemsa’s stain, Wright’s stain etc). The blood smear is stain positively with Perls’ reaction (in contrast to