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Figure 17.15 Aspergillosis lung. A, Acute angled septate hyphae
lying in necrotic debris and acute inflammatory exudates in lung abscess.
B, Organisms, Apergillus flavus, are best identified with a special stain
for fungi, Gomory’s methenamine silver (GMS).

5. Cryptococcosis. It is caused by Cryptococcus neoformans II. Emphysema
which is round yeast having a halo around it due to shrinkage III. Bronchial asthma
in tissue sections. The infection occurs from infection by IV. Bronchiectasis CHAPTER 17
inhalation of pigeon droppings. The lesions in the body may Chronic bronchitis and emphysema are quite common
range from a small parenchymal granuloma in the lung to and often occur together. Now, small airways disease
cryptococcal meningitis. involving inflammation of small bronchi and bronchioles
6. Coccidioidomycosis. Coccidioidomycosis is caused by (bronchiolitis) has also been added to the group of COPD.
Coccidioides immitis which are spherical spores. The infection
in human beings is acquired by close contact with infected CHRONIC BRONCHITIS
dogs. The lesions consist of peripheral parenchymal Chronic bronchitis is a common condition defined clinically
granuloma in the lung. as persistent cough with expectoration on most days for at
7. Blastomycosis. It is an uncommon condition caused by least three months of the year for two or more consecutive
Blastomyces dermatitidis. The lesions result from inhalation years. The cough is caused by oversecretion of mucus. In The Respiratory System
of spores in the ground. Pathological features may present spite of its name, chronic inflammation of the bronchi is not
as Ghon’s complex-like lesion, as a pneumonic consolidation, a prominent feature. The condition is more common in
and as multiple skin nodules. middle-aged males than females; approximately 20% of adult
men and 5% of adult women have chronic bronchitis, but
PULMONARY TUBERCULOSIS only a minority of them develop serious disabling COPD or
cor pulmonale. Quite frequently, chronic bronchitis is
The classical and most common example of chronic infection associated with emphysema.
of the lungs is pulmonary tuberculosis. Pulmonary lesions ETIOPATHOGENESIS. The two most important etiologic
caused by Mycobacterium tuberculosis and other mycobacteria factors responsible for majority of cases of chronic bronchitis
have already been discussed along with general aspects of are: cigarette smoking and atmospheric pollution. Other
tuberculosis and other granulomatous inflammations in contributory factors are occupation, infection, familial and
Chapter 6.
genetic factors.
1. Smoking. The most commonly identified factor
CHRONIC OBSTRUCTIVE PULMONARY DISEASE
implicated in causation of chronic bronchitis and in
Chronic obstructive pulmonary disease (COPD) or chronic emphysema is heavy smoking. Heavy cigarette smokers have
obstructive airway disease (COAD) are commonly used 4 to 10 times higher proneness to develop chronic bronchitis.
clinical terms for a group of pathological conditions in which Prolonged cigarette smoking appears to act on the lungs in a
there is chronic, partial or complete, obstruction to the airflow number of ways:
at any level from trachea to the smallest airways resulting in i) It impairs ciliary movement.
functional disability of the lungs i.e. they are diffuse lung ii) It inhibits the function of alveolar macrophages.
diseases. The following 4 entities are included in COPD: iii) It leads to hypertrophy and hyperplasia of mucus-
I. Chronic bronchitis secreting glands.