YSTEMICISTS

Pathology RS

Title : Tuberculosis ( TB ) .

Done by: Farah Al-Fraihat .

A man may die, nations may rise and fall ..But an idea lives on

Tuberculosis (TB)

disease caused is communicable chronic granulomatous : TB

It usually involves the lungs , Mycobacterium tuberculosisby

but may affect any organ or tissue in the body .

ETIOLOGY : M. tuberculosis hominis is responsible for most

cases of tuberculosis , Oropharyngeal and intestinal

tuberculosis contracted by drinking milk contaminated with

Mycobacterium bovis , Mycobacterium avium complex cause

disease in 10% to 30% of patients with AIDS.

> by coughing , sneezing or - aerosols: through TRANSMISSION

any other way that will expel bacilli into the air ,

Immunosuppressed patients have higher chance of getting

infected .

PATHOGENESIS :

- TB bacilli taken up by alveolar macrophages through action

of receptors on their surface

- Bacilli inhibit microbial killing by interfering with

phagolysosomal function

- Proliferation of bacilli inside alveolar macrophages, then

released→bacteremia .

3 weeks later -> cell mediated immunity develop (CD4+TH1) ->

release IFN gama -> recruitment of monocytes -> caseating

granuloma .

SYMPTOMS AND SIGNS :

LATER SYMPTOMS EARLY SYMPTOMS

Night sweats, fever, cough with purulent secretions and haemoptysis, dyspnoea, chest pain, and hoarseness.

Common cold symptoms , Fatigue, fever, a minimally productive cough of yellow or green sputum and a general feeling of malaise.

TYPES OF TB :

: PIRMARY TB) 1

* Subpleural caseating granuloma Ghon focus

* Enlarged hilar LNs with caseation Ghon Complex

Ghon focus in parenchyma + nodal involvement .

Fibrosis calcification : Ranke complex

Fate : Good : healing of small and large foci , may harbor

viable bacilli for years , perhaps for life and thus be nidus for

reactivation a later time when host defenses are

compromised .

SECONDARY TB : ( reactivation )) 2

After primary (< 5% ) , Reactivation of old focus, Reinfection

with a virulent strain .

infection usually at apex about 2 cm.size , Cavitation common

POSITIVElymph node involvement less prominent , Sputum ,

for TB bacilli .

SYMPTOMS : hemoptysis , fever , loss of weight , night sweats

and pleuritic pain .

OUTCOME : may heal or become progressive .

r after This can occu PROGRESSIVE PULMONARY TB :) 3

primary or secondary TB , along the following routes :

• Tracheobronchial tree & lymphatics :

– Tuberculous bronchopneumonia OR Miliary pulmonary

disease.

– Pleural involvement leads to effusion, empyema or

obliterative fibrous pleuritis

• Spread through trachea to larynx leads to Laryngeal TB .

LIARY TB : (SEVERE FORM )LMI) 4

Hematogenous spread, All organs involved show : multiple

rounded yellowish equal sized small foci .

ISOLATED ORGAN TB : ( through blood )) 5

– Tuberculous salpingitis & endometritis lead to sterility

– Meninges (tuberculous meningitis)

– Vertebral TB POTT’s Disease

– Adrenal gland Addisons disease.

– Tuberculous lymphadenitis: Most frequent form of

extrapulmonary tuberculosis, cervical region (Scrofula).

– Renal infection Tuberculous chronic Pyelonephritis,

nephrotic syndrome

– Male Genital system Tuberculous epididymo-orchitis &

prostatitis sterility

SECONDARY AMYLOIDOSIS Chronic TB •

: ( due to drink contaminated INTESTINAL TUBERCULOSIS) 6

milk ) , In developed countries today as a complication of

advanced secondary TB due to swallowing of coughed-up

infective material .

: TUBERCULOSIS in HIV) 7

Usually secondary reactivation TB , M.avium common in late

stages .

. munityNO caseation due to poor im

Diagnosis : X-ray , Clinical picture , sputum (direct

examination for Acid fast bacilli by ZN, Auramine-rhodamine

stains, PCR ) , culture of sputum about 6 weeks .

In chest X-ray : Multi nodular infiltrate above or behind the

clavicle with or without pleural effusion unilaterally or

bilaterally .

-, by injecting PPD into skin (48 ( tuberculin test )In skin test :

72 hrs )

Problems of this test : It indicates hypersensitivity to bacilli

but does not differentiate infection from active disease

• False negative in Miliary TB , AIDS, sarcoidosis some viral

diseases , Hodgkin’s disease , malnutrition…

• False positive in atypical mycobacterial infection .

: YEARS OF THIS LEC ( V.IMPORTANT )

milliary TB: system TB-Multi. 1

2. mismatched :

a) vertebral TB - Pott's disease

b) tuberculous salpingitis - sterility .

c) adrenal gland - addison disease

d) chronic TB - secondary amyloidosis

scrofula -tuberculos lymphadenitis in axillary region e)