Pathological changes in various organs due to malaria

1.. Spleen

i)                    Enlarged spleen

ii)                   Slate grey or black colour .

iii)                 The capsule is thin or thick if it is acute or chronic .

iv)                 Consistency – Soft in acute cases , firm in chronic cases

v)                  Microscopically –

a)      Congested splenic sinusoids .

b)      Haemozoin and haemosiderin are found in abundance .

c)       Malpighian corpuscles are free from pigments and parasites .

d)      Increased macrophage cells .

2.. Liver

i)                    Enlarged liver

ii)                   Dark chocolate red or slate grey or black colour .

iii)                 Dilated lobules

iv)                 Microscopically –

a)      Dialated central veins

b)      Kupffer’s cells are increased .

c)       Fatty degeneration of liver cells .

d)      Parasites are found in red cells .

3.. Bone marrow – There will be little changes in bone marrow of long bones in acute case . In chronic case the upper and lower third of the long bones may be reddish brown in colour , even it may be slate grey or black colour . There will be formation of red formative marro .

      Microscopically –

i)                     Hyperplasia of R.E cell

ii)                   Haemozoin pigment will be present .

iii)                 There will be increased number of nucleated R.B.C and reticulocyte .

iv)                 Malarial parasite is present in R.B.C

4.. Brain - 

a)      The capillaries of brain tissue will distended and may be occluded by the infected R.B.C . This occurs due to pernicious malaria

b)      Cut surface of brain shows slate grey cortex

c)       Multiple punciform haemorrhage is found

d)      Areas of infract may be found .

e)      Microscopically –

i)                    Dilation and congestion of cerebral capillaries .

ii)                   Perivascular haemorrhage .

iii)                 Presence of scattered areas of softening ad softening areas may be invaded by glial cells forming malarial granulomas .

5..  Gastrointestinal tract –

a)      The mucous membrane shows pigmentation of slate grey colour .

b)      Punctiform haemorrhages may be present .

c)       Microscopically –

i)                    Capillaries of mucous and submucous membrane will be congested

ii)                   There will be presence of parasitised R.B.C in the capillaries .

6.. Adrenal gland –

a)      There will be necrosis of zona fasiculata .

b)      There will be haemorrhage in zona reticulata .

c)       There will be presence of parasitised R.B.C and pigmented phagocytes in sinusoidal capillaries