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1. CELL INJURY-II
GANGRENE
Dr. Sharayu Patil

3. Gangrene
■ DEFINITION:
Is a form of necrosis of tissue with superadded
putrefaction.
■ The type of necrosis is usually coagulative d/t ischemia.
■ Eg- gangrene of bowel or limb.
■ TYPES:
1. Dry
2. Wet
3. Gas

4. Dry gangrene
This form of gangrene begins in distal part of limb d/t
ischemia.
Eg-toes and feet of an old pt d/t arteriosclerosis
Gross:
■ Affected part is dry and shrunken, dark black.
■ Line of separation usually brings about complete
separation with following of gangrenous tissue.

5. DRY
GANGRENE

6. Microscopy:
1. Necrosis with
smudging of
the tissue
2. The line of
separation
consist of
inflammatory
granulation
tissue

7. Wet gangrene
■ Occurs in naturally moist tissue such as mouth, bowel,
lung, cervix, vulva.
■ Eg- diabetic foot, bed sores
■ Gross:
1. Affected part is soft swollen putried rotten and dark.
2. Eg- gangrene of bowel d/t strangulated hernia.

8. Wet gangrene

9. Microscopy:
1. Coagulation
necrosis with
stuffing of
affected part
with blood.
2. Ulceration of
mucosa and
intense
inflammatory
infiltration.
3. The line of
demarcation is
not clear.

10. DRY v/s WET GANGRENE

11. Gas gangrene
■ Special form of wet gangrene
■ Caused by gas forming clostridia
■ Clostridia produce various toxins which produce necrosis,
oedema locally and when absorbed, produce systemic
manifestations.
■ Gross:
1. Swollen, oedematous, painful, crepitant d/t
accumulation of gas bubbles within tissue
2. Later it becomes dark, blacken, foul smelling

12. GAS GANGRENE
of LARGE INTESTINE
of FOOT

13. Microscopy:
1. The muscle fibres
undergo
coagulative
necrosis with
liquefaction.
2. Large no. of gram
positive
bacteria.(Fig. C)
3. At periphery, zone
of leucocytic
infiltration,
oedema,
congestion
4. Capillary and
venous thrombi
are common.