Tuberculosis

Question 1

Pulmonary TB

Pathology of primary complex

Answer 1

1-2 cm Caseous necrosis

Area: subpleura, base of upper lobe, apex of lower

Granulomatous inflammation

Small tubercles in lymphatics (enlarged) (hilar, tracheobronchial nodes)

Gohn complex= Lung + nodal disease

Question 2

Pulmonary TB

Consequences

Answer 2

Healing
Local spread
Haematogenous dissemination

Question 3

Pulm TB

Healing

Answer 3

Lesions walled off by fibrosis
Dystrophic calcification
Lymph node heal slower

Question 4

Pulmonary TB

Local spread pathogenesis

Answer 4

Liquification (superadded infection) -> extend to pleura

Caseous matter erode into small bronchus-> disseminate into healthy lung-> tuberculous Pneumonia

Question 5

Tuberculous bronchopneumonia

Pathology

Answer 5

:

Erosion of large bronchi(due: enlarged lymph nodes)-> larger dissemination of foci of caseation in lung.

Question 6

Pulm TB
Haematological spread
Pathogenesis

Answer 6

Drainage of midiastinal lymph nodes via thoracic duct into subclavian vein-> bacteraemia/dissemination through body

Rupture of caseous material(lymph nodes) -> pulm artery/vein-> dissemination in lung/body

Question 7

Haematological spread result

Incidental bateraemia

Answer 7

Inevitable
No immediate consequence
Sent to high O² region-> lie dormant

Question 8

Haematological spread result

Miliary TB

Answer 8

Tubicles scattered throughout body

Heavy haematogenous dissemination (erosion of large lymph node into vessel)

Each tubercle is a granuloma

Question 9

Haematological spread result

Sub acute TB

Answer 9

Similar to Miliary

But: larger tubicles, less organisms & tubicles

Question 10

Haematological spread result

Organ TB

Answer 10

Chronic TB of organ
Due to: minimal haematogenous dissemination
Primary sight healed

Question 11

Post primary TB

Consequences

Answer 11

Healing, fibrosis, calcification
Progressive fibrocaseous disease
Distant spread

Question 12

Progressive fibrocaseous disease

Answer 12

Erosion into bronchus
Cavity formation:
Inner caseous tissue 
Middle zone of granu.inflam and gran.tissue
Outer fibrous layer

Question 13

Distant spread

Answer 13

Proximally to trachea, larynx, tonsillar region

Haematological spread

Question 14

Pulm TB

Consequences

Answer 14

Severe fibrosis & scarring
Bronchiectasis
Cavitation
Spread to pleura

Question 15

Extra-Pulmonary TB

Route of spread

Answer 15

Direct
Lymphatic
Haematogenous (pulm/systemic)
Transcoelomic