대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Accessory Cardiac Bronchus, Non-small cell lung cancer

Radiologic Findings

Thin-section CT scans show an anomalous bronchus originating from the medial wall of the bronchus intermedius.
The supernumerary bronchus is ectatic, and is associated with a small accessory lobe.

2D reformation image (below) obtained in an oblique, sagittal plane shows the accessory cardiac bronchus (arrow) arising from the bronchus intermedius.

An 11-mm-sized cavitary nodule is seen in right lower lobe.
CT-guided aspiration biopsy (below) was beautifully done by our Fellow Dr. Po Song Yang,
and the cavitary nodule proved a non-small cell lung cancer (T1 N0 stage).

Brief Review

The accessory cardiac bronchus is a rare congenital anomaly of the tracheobronchial tree that arises from the medial wall of the bronchus intermedius.

According to McGuinness et al,
In all six cases, a distinct airway could be identified originating from the medial wall of the bronchus intermedius. Associated lung parenchymal tissue was identified in four cases,
while in three cases a discrete soft-tissue mass was seen,
presumably representing vascularized bronchial or vestigial parenchymal tissue.
In two cases, the lumen of the airway was filled with debris.
Recognition of this anomaly is important, as associated clinical complications,
including recurrent episodes of both infection and hemoptysis, may be anticipated in a small percentage of patients.

According to Ghaye et al,
Accessory cardiac bronchus (ACB) has been described mainly as isolated case reports in the literature.
We report nine consecutive cases of ACB, which occurred in five males and four females and were detected in 11,159 routine spiral CT examinations of the chest, performed between 1994 and 1998.
Frequency of the anomaly was 0.08 %.
Accessory cardiac bronchus originated from the intermediate bronchus in eight cases and from the right main bronchus in one case.
Mean largest diameter of ACB was 8.7 mm (range 4.0-13.8 mm) and mean length was 11.9 mm (range 4.2-23.4 mm). An abnormal pulmonary artery was observed in one case.
Six bronchi presented with a blind distal extremity and three showed a ventilated lobulus with a mean largest diameter of 37.5 mm (range 18.6-62.0 mm).
All ACBs were documented by 3D shaded-surface display (SSD) and virtual endobronchial navigation, which may facilitate the diagnosis.

References

1. McGuinness G, Naidich DP, Garay SM, Davis AL, Boyd AD, Mizrachi HH. Accessory cardiac bronchus: CT features and clinical significance. Radiology 1993 Nov;189(2):563-6

2. Ghaye B, Kos X, Dondelinger RF. Accessory cardiac bronchus: 3D CT demonstration in nine cases. Eur Radiol 1999;9(1):45-8

Keywords

Airway, Congenital, Bronchial abnormlity,