Answer B. Bronchial Atresia
Discussion
Bronchial atresia is a rare congenital anomaly caused by focal
interruption of a lobar, segmental or subsegmental bronchus. The exact
pathogenesis of bronchial atresia remains unknown but there are two
hypotheses which exist. One theory state that bronchial atresia is a
result of vascular injury that occurs during early fetal development.
The second postulates that it occurs due to the separation of the
developing bronchial bud during normal lung maturation1.
Often, bronchial atresia is an incidental finding and patients are
usually asymptomatic. One-third of patients report symptoms of cough,
shortness of breath and recurrent infections and to a lesser extent
wheezing, hemoptysis, chest pain, or pneumothorax2,3. In our
patient, chronic cough and weight loss was likely secondary to pyloric
stricture causing vomiting with subsequent aspiration of gastric
contents. At his two-month follow-up after pylorus dilation, he had no
symptoms of lingering cough.
Chest Xray usually shows nonspecific findings in bronchial atresia.
Although upon careful examination, findings of an elongated opacity with
focus of hyperinflation may increase your suspicion for bronchial
atresia should be higher. Chest CT is more specific for the diagnosis of
bronchial atresia. Usually, mucoceles and area of hyperinflation distal
to the affected segment are what is seen. Rarely, if there is no mucoid
impaction, an air-filled bronchus is visualized. This was the case in
our patient, where the distal lung supplied by the atretic segment
appeared hyperlucent secondary to air trapping and reduced pulmonary
blood volume. Hyperinflation is typically present because of collateral
ventilation through the bronchoalveolar channels of Lambert, pores of
Kohn, or interbronchiolar channels4. Flexible bronchoscopy is
another modality through which diagnosis of bronchial atresia can be
made, which reveals a blind ending bronchus.
The management of bronchial atresia remains controversial. For
patients who are asymptomatic, no active treatment is indicated.
However, in patients who have recurrent infections and significant
shortness of breath, surgical intervention is sought. While radiographic
findings are essential for identifying patients who may have bronchial
atresia, bronchoscopy confirmation should always be attempted to rule
out other possible etiologies for segmental hyperinflation5.
Chest radiographs in CPAM usually demonstrates obvious multi-cystic
air-filled lesions (Answer A is incorrect). In pulmonary sequestration,
Chest CT demonstrates typical appearance of complex mass with or without
cystic changes. This mass can be fluid or air filled microcysts or as a
large cavitating lesion with an air fluid level (Answer C is
incorrect). Whereas in Mucocele or mucoid impaction, imaging
demonstrates classic “finger in glove” appearance from formation of
mucoid in the distal bronchus (Answer D is incorrect).
References
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Wang Y, Dai W, Sun Y, Chu X, Yang B, Zhao M. Congenital bronchial atresia: diagnosis and treatment. Int J Med Sci. 2012;9(3):207-12.
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Psathakis K, Eleftheriou D, Boulas P, Mermigkis C, Tsintiris K.
Congenital bronchial atresia presenting as a cavitary lesion on chest
radiography: a case report. Cases J. 2009 Jan 07;2(1):17
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de Melo ASA. Diagnostic imaging in bronchial atresia. Radiol Bras.
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33854270; PMCID: PMC8029932.
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Mahajan AK, Rahimi R, Vanderlaan P, Folch E, Gangadharan S, et al.
(2017) Unique Approach to Diagnosing and Treating Congenital Bronchial
Atresia (CBA): A Case Series. J Pulm Respir Med 7: 402. doi:
10.4172/2161-105X.100040