Follicular bronchiolitis
Updates to Article Attributes
Follicular bronchiolitis (FB) is a nonneoplastic primary polyclonal B cell hyperplasia of the bronchus-associated lymphoid tissue (BALT) due to chronic exposure to antigens in those with underlying collagen vascular or immune deficiency diseases which usually manifested as small centrilobular ground glass nodules with lower lobe distribution.
Pathology
It is defined as lymphoid hyperplasia of the BALT and histologically characterised by polyclonal B cell hyperplasia of the lymphoid follicles with reactive germinal centres principally distributed along bronchioles with only minimal infiltration of alveolar septaesepta.
Associations
Many cases of follicular bronchiolitis are associated with various systemic illnesses which include
-
collagen vascular
diseasesdisease/ connective tissue diseases 1,2 - immunodeficiency states, both congenital and acquired:
- idiopathic
Radiographic features
HRCT chest
A key feature described with follicular bronchiolitis on HRCT includes small ground glass centrilobular nodules of 3 mm diameter in lower lobes that are variably associated with peribronchial nodules 1.
Other features (albeit, albeit non-specific) include, include:
Treatment and prognosis
Treatment should target the underlying condition, as well as administration of steroidsteroids and immunosuppressants. The overall prognosis will dependdepends on the underlying or associated abnormality. Some cases may respond to macrolide antibiotics 6.
Differential diagnosis
- hypersensitivity pneumonitis: history of environmental/organic antigen exposure
- respiratory bronchiolitis: history of smoking
- infection
-<p><strong>Follicular bronchiolitis (FB)</strong> is a nonneoplastic primary polyclonal B cell hyperplasia of the bronchus-associated lymphoid tissue (<strong>BALT</strong>) due to chronic exposure to antigens in those with underlying collagen vascular or immune deficiency diseases which usually manifested as small centrilobular ground glass nodules with lower lobe distribution. </p><h4>Pathology</h4><p>It is defined as lymphoid hyperplasia of the BALT and histologically characterised by polyclonal B cell hyperplasia of the lymphoid follicles with reactive germinal centres principally distributed along bronchioles with only minimal infiltration of alveolar septae.</p><h5>Associations</h5><p>Many cases of follicular bronchiolitis are associated with various systemic illnesses which include</p><ul>-<li>collagen vascular diseases / <a href="/articles/connective-tissue-diseases">connective tissue diseases</a> <sup>1,2</sup><ul>-<li><a href="/articles/sjogren-syndrome">Sjogren syndrome </a></li>- +<p><strong>Follicular bronchiolitis (FB)</strong> is a nonneoplastic primary polyclonal B cell hyperplasia of the bronchus-associated lymphoid tissue (<strong>BALT</strong>) due to chronic exposure to antigens in those with underlying collagen vascular or immune deficiency diseases which usually manifested as small centrilobular ground glass nodules with lower lobe distribution. </p><h4>Pathology</h4><p>It is defined as lymphoid hyperplasia of the BALT and histologically characterised by polyclonal B cell hyperplasia of the lymphoid follicles with reactive germinal centres principally distributed along bronchioles with only minimal infiltration of alveolar septa.</p><h5>Associations</h5><p>Many cases of follicular bronchiolitis are associated with various systemic illnesses which include</p><ul>
- +<li>
- +<a title="Collagen vascular disease" href="/articles/connective-tissue-disease">collagen vascular disease</a> / <a href="/articles/connective-tissue-diseases">connective tissue diseases</a> <sup>1,2</sup><ul>
- +<li>
- +<a title="Sjögren syndrome" href="/articles/sjogren-syndrome-1">Sjögren syndrome</a> - see <a title="Sjögren syndrome (thoracic manifestations)" href="/articles/sjogren-syndrome-thoracic-manifestations-1">Sjögren syndrome (thoracic manifestations)</a>
- +</li>
-<li>immunodeficiency states both congenital and acquired:<ul><li>- +<li>immunodeficiency states, both congenital and acquired:<ul><li>
-</ul><h4>Radiographic features</h4><h5>HRCT chest</h5><p>A key feature described with follicular bronchiolitis on HRCT includes small <a href="/articles/ground-glass-opacification-3">ground glass </a><a href="/articles/centrilobular-lung-nodules-1">centrilobular nodules</a> of 3 mm diameter in lower lobes that are variably associated with peribronchial nodules <sup>1</sup>.</p><p>Other features (albeit non-specific) include:</p><ul>- +</ul><h4>Radiographic features</h4><h5>HRCT chest</h5><p>A key feature described with follicular bronchiolitis on HRCT includes small <a href="/articles/ground-glass-opacification-3">ground glass </a><a href="/articles/centrilobular-lung-nodules-1">centrilobular nodules</a> of 3 mm diameter in lower lobes that are variably associated with peribronchial nodules <sup>1</sup>.</p><p>Other features, albeit non-specific, include:</p><ul>
-</ul><h4>Treatment and prognosis</h4><p>Treatment should target the underlying condition as well as administration of steroid and immunosuppressants. The overall prognosis will depend on the underlying or associated abnormality. Some cases may respond to macrolide antibiotics <sup>6</sup>.</p><h4>Differential diagnosis</h4><ul>- +</ul><h4>Treatment and prognosis</h4><p>Treatment should target the underlying condition, as well as administration of steroids and immunosuppressants. The overall prognosis depends on the underlying or associated abnormality. Some cases may respond to macrolide antibiotics <sup>6</sup>.</p><h4>Differential diagnosis</h4><ul>
Image 1 CT (lung window) ( create )
Image 2 CT (lung window) ( update )
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