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A 40-year-old male patient who currently smokes presented with complaints of cough and low-grade fever for 6 months. Endobronchial carcinoma with collapse of a distal right lung segment was initially considered at chest radiography and bronchoscopy. Contrast-enhanced CT revealed intralobar sequestration in the lower lobe of the right lung, with an enhancing lesion showing endobronchial extension. MRI showed better demarcation between the neoplastic lesion and sequestration (Figs 1, 2; Movie). The patient underwent bilobectomy (right middle and lower lobes) with complete excision of the tumor and sequestered lung tissue. Postresection histopathologic results confirmed the lesion to be a low-grade mucoepidermoid carcinoma (MEC) arising from the bronchus of the sequestered lung segment.
Figure 1:
(A) Chest radiograph shows right infrahilar opacity (thin arrow) continuous with distal triangular opacity in the right paracardiac region (thick arrow). (B–D) Coronal and axial contrast-enhanced chest CT images show a lobulated enhancing lesion (thin arrow) with endobronchial extension into the bronchus intermedius (dotted arrow) of the sequestered lung (thick arrow). (E, F) Sagittal and axial T2-weighted MR images show a well-defined heterogeneous hyperintense lesion with cystic spaces (thin arrow), distinct from the sequestered lung (thick arrow).
Figure 2:
(A) Volume-rendered CT image of the chest and upper abdomen shows the intralobar sequestered lung (thick arrow) and faint lucency representing lesion (thin arrow) within it. A dilated aberrant artery (red arrows) arising from the abdominal aorta distal to the origin of the celiac trunk (yellow arrow) and venous drainage into the inferior pulmonary vein (blue arrows) are observed. (B) Histopathologic image shows fibrocollagenous tissue infiltrated by cytologically bland mucin-secreting glandular, intermediate and squamoid cells (arrow). (Hematoxylin-eosin stain; magnification, 40×.) (C) Mucicarmine stain highlights the presence of mucin (arrow). (D) Immunohistochemical analysis of tumor cells indicated p40 positivity (arrow).
Movie:
Sequential axial chest CT sections show the tumor, sequestered lung segment and its vascular supply from the abdominal aorta. Volume-rendered three-dimensional images show the sequestrated lung segment receiving vascular supply from the fusiform dilated aberrant artery arising from the abdominal aorta distal to the origin of the celiac artery.
MECs of the lung are rare, salivary gland-type tumors arising from the submucosal glands of bronchi and constitute 0.2% of all lung tumors (1). Bronchopulmonary sequestration is a congenital malformation of lung tissue characterized by lack of normal communication with the tracheobronchial tree. Sequestrations receive systemic arterial supply most commonly from the thoracic aorta (73%) followed by the upper abdominal aorta proximal to the origin of the celiac artery (21%) (2,3). These images demonstrate an unusual case of MEC arising from the bronchus of an intralobar pulmonary sequestration with aberrant supply from the abdominal aorta distal to the celiac origin.
Acknowledgments
Acknowledgments
G. Veereshalingam, CT Technician, Department of Radiodiagnosis, Basavatarakam Indo American Cancer Hospital & Research Institute.
Footnotes
Authors declared no funding for this work.
Disclosures of conflicts of interest: S.Y. No relevant relationships. A.M. No relevant relationships. D.F. No relevant relationships. V.K. No relevant relationships.
Keywords: CT, MR Imaging, Pulmonary, Thorax, Vascular, Lung, Aorta, Arteries, Congenital, Neoplasms-Primary, Oncology
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