대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Endobronchial pleomorphic adenoma

Radiologic Findings

Fig 1. Chest PA shows a well-defined nodule in the carina and right main bronchus.
Fig 2-5. CT scans reveals a 2.0-cm well-circumscribed lobulated endoluminal nodule at the carina and right main bronchus, showing enhancement. The volume of the right lung has been decreased with right side mediastinal shifting. There was no lung parenchymal abnormalities.
Fig 6. At bronchoscopy, a smooth polypoid mass obstructing approximately 75% of the lumen was identified at the distal trachea.

Brief Review

Pleomorphic adenomas are the most common tumors of the salivary glands. They are rare in the lung, and have been reported to occur in a broad age range, from 8 to 74 years old. As their salivary gland counterparts, they are benign neoplasms that in the lung are believed to arise from the submucosal bronchial glands for which they occur mostly as endobronchial lesions. However, lesions occurring in the distal lung parenchyma have been reported. They are biphasic neoplasms with epithelial and myoepithelial cells and a mesenchymal component that can be mucoid, myxoid or chondromyxoid stroma. The pathologic differential diagnosis includes other salivary gland-type neoplasms such as epithelial myoepithelial carcinoma and myoepithelial carcinoma, metastatic salivary gland neoplasms of head and neck, hamartomas and carcinosarcoma pleomorphic adenoma. Pleomorphic adenomas are benign lesions that can rarely show features of malignant transformation including infiltrative borders, necrosis, increased mitoses and angioinvasion. The clinical presentation depends on their location in the respiratory tract. Endoluminal polypoid lesions present with shortness of breath and dyspnea while parenchymal lesions are incidental radiographic findings. Bronchoscopic or surgical removal is the treatment of choice. Long-term follow-up after treatment is advisable only if malignant transformation is present.

References

1. Ali SR, Arrossi AV, Mehta AC, Frye L, Mazzone P, Almeida F. Endobronchial pleomorphic adenoma. Oxf Med Case Reports. 2016 Dec 1;2016(12):omw090. doi: 10.1093/omcr/omw090. PMID: 28031854; PMCID: PMC5184838.

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