Bronchiectasis
Epidemiology:
- Associated with a
variety of conditions:
- Hereditary:
- cystic
fibrosis
- intralobar
sequestration of the lung
- immunodeficiency
- primary
ciliary dyskinesia
- Kartagener
syndrome
- Postinfectious:
- Necrotizing
pneumonia
- TB, Staph. aureus,
H. influenzae, Pseudomonas
- Viruses
(adenovirus, influenza virus, HIV)
- Fungi
(Aspergillus)
- Bronchial obstruction
- Tumour
- Foreign
bodies
- Mucous
- Others:
- RA
- SLE
- IBD
- Post-transplant
(lung or bone marrow – GVHD)
Common sites:
Gross features:
- lower lobes >
upper lobes
- vertical air
passages particularly involved
- distal bronchi and
bronchioles most involved
- may be sharply localized
to a single segment when associated with tumour
or foreign body
- dilated airways
- cylindrical, fusiform, or saccular
- can usually be
followed to the pleural surfaces
- normally
can’t see bronchioles beyond 2-3cm from pleura
- cysts filled
with mucopurulent secretions
Histologic features:
- damage to airway
walls
- destruction of
smooth muscle and elastic tissue
- fibrosis
- dilation
- acute and chronic
inflammatory exudation within walls of bronchi and bronchioles
- desquamation of
the lining epithelium
- areas of
necrotizing ulceration
- pseudostratification of the columnar cells maybe
- squamous metaplasia
maybe
- abscess sometimes
with complete destruction of bronchial or bronchiolar walls
- fibrosis of
bronchial and bronchiolar walls and peribronchiolar
areas
- bronchiolitis obliterans
in severe cases
Immunophenotype:
Marker:
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Sensitivity:
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Specificity:
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Molecular features:
Other features:
- permanent dilation
of bronchi and bronchioles caused by destructikon
of the muscle and elastic tissue, resulting from or associated with
chronic necrotizing infections
- obstruction and
infection are most important drivers
- flora involved:
- staph
- strep
- pneumococci
- enteric
- anaerobic
- microaerophilic
- Haemophilus
influenza
- Pseudomonas aeruginosa
- Aspergillus in ABPA
- Complications:
- Cor pulmonale
- Metastatic brain abscesses
- amyloidosis
References: