Diagnostic imaging of congenital pulmonary aplasia in a dog

Abstract

A 2-year-old, female Pomeranian dog was referred for dyspnea. Thoracic radiographs revealed left-sided mediastinal shift, increased soft tissue opacity in the caudal aspect of left thorax with loss of the left diaphragmatic silhouette, and dorsal elevation of mediastinal structures and heart from the sternum by lung tissue. The left main bronchus was visualized as an air-bronchogram and observed to abruptly discontinue at the level of the 10th rib. Thoracic computed tomography (CT) revealed absence of the left lung parenchyma and left pulmonary vessels with a rudimentary left main bronchus. The case was congenital pulmonary aplasia diagnosed via radiography and CT.

Clinical and imaging features of presumptive congenital pulmonary underdevelopment with complications in two dogs

“…In these cases, especially, thoracic radiography is readily available at a low cost for long‐term follow‐up. However, radiographic features, such as mediastinal shift, collapsed affected lung lobe and hyperlucent contralateral lung lobe in previous veterinary reports and humans with congenital pulmonary underdevelopment are difficult to diagnose as these features mimic other chronic lung diseases 7,10,11,18,19,24 . In both cases in this report, lung parenchymal atelectasis was considered for the affected lung lobes on thoracic radiographs, but CT scans confirmed congenital pulmonary lesions without alveolar structure.…”

“…There are four previous case reports on pulmonary underdevelopment in veterinary medicine. Of these, three cases had a presumptive diagnosis of aplasia of the left lung, hypoplasia of the left cranial lung lobe and agenesis of the right lung based on the CT scan 10–12 . In the remaining case, hypoplasia of the left cranial lung lobe with congenital lobar emphysema was diagnosed by CT imaging and histopathologic examination 24 .…”

“…In these cases, a presumptive diagnosis of congenital pulmonary underdevelopment, such as aplasia or hypoplasia, was made on the imaging tests alone, without the histological examination. The definitive diagnosis of agenesis and aplasia is made through postmortem or histological examination, but agenesis without the entire lung lobe structure or aplasia with the rudimentary bronchus without pulmonary parenchyma and vasculatures can be a presumptive diagnosis through the advanced imaging tests in human and veterinary medicine 1,2,4,7,8,11,13–15 . On the other hand, diagnosis of the congenital pulmonary hypoplasia in human medicine has several histological diagnostic criteria, but there is no clear golden standard 16 .…”

“…Only a few reports have been described in literature concerning congenital pulmonary underdevelopment in veterinary medicine 10–12 . In all these cases, the age at diagnosis was under 2 years, and no reports exist on the known complications in adults with pulmonary congenital diseases in human medicine.…”

“…2,[6][7][8][9] Only a few reports have been described in literature concerning congenital pulmonary underdevelopment in veterinary medicine. [10][11][12] In all these cases, the age at diagnosis was under 2 years, and no reports exist on the known complications in adults with pulmonary congenital diseases in human medicine. To our knowledge, this is the first report on the long-term follow-up of complications that may occur in geriatric dogs with a presumptive diagnosis of congenital pulmonary underdevelopment.…”