Page 501 - Textbook of Pathology, 6th Edition

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MORPHOLOGIC FEATURES. The disease charac-
teristically affects distal bronchi and bronchioles beyond
the segmental bronchi.
Grossly, the lungs may be involved diffusely or
segmentally. Bilateral involvement of lower lobes occurs
most frequently. More vertical air passages of left lower
lobe are more often involved than the right. The pleura is
usually fibrotic and thickened with adhesions to the chest
wall. The dilated airways, depending upon their gross or
bronchographic appearance, have been subclassified into
the following different types (Fig. 17.22):
i) Cylindrical: the most common type characterised by
tube-like bronchial dilatation.
ii) Fusiform: having spindle-shaped bronchial dilatation.
iii) Saccular: having rounded sac-like bronchial distension.
iv) Varicose: having irregular bronchial enlargements.

Cut surface of the affected lobes, generally the lower
zones, shows characteristic honey-combed appearance. The
bronchi are extensively dilated nearly to the pleura, their
walls are thickened and the lumina are filled with mucus or
Figure 17.22 Types of bronchial dilatations in bronchiectasis. muco-pus. The intervening lung parenchyma is reduced and
fibrotic (Fig. 17.23).
v) Atopic bronchial asthma patients have often positive family
history of allergic diseases and may rarely develop diffuse Microscopically, fully-developed cases show the CHAPTER 17
bronchiectasis. following histologic features (Fig. 17.24):
i) The bronchial epithelium may be normal, ulcerated
2. Obstruction. Post-obstructive bronchiectasis, unlike the or may show squamous metaplasia.
congenital-hereditary forms, is of the localised variety, ii) The bronchial wall shows infiltration by acute and
usually confined to one part of the bronchial system. The chronic inflammatory cells and destruction of normal
causes of endobronchial obstruction include foreign bodies, muscle and elastic tissue with replacement by fibrosis.
endobronchial tumours, compression by enlarged hilar
lymph nodes and post-inflammatory scarring (e.g. in healed iii) The intervening lung parenchyma shows fibrosis,
while the surrounding lung tissue shows changes of
tuberculosis) all of which favour the development of post- interstitial pneumonia.
obstructive bronchiectasis.
iv) The pleura in the affected area is adherent and shows The Respiratory System
3. As secondary complication. Necrotising pneumonias such bands of fibrous tissue between the bronchus and the
as in staphylococcal suppurative pneumonia and tuberculosis pleura.
may develop bronchiectasis as a complication.

Figure 17.23 Bronchiectasis of the lung. Sectioned surface shows honey-combed appearance of the lung in the lower lobe where many thick-
walled dilated cavities with cartilaginous wall are seen (arrow).