An infrequent cause of persistent cough: endobronchial lipoma.

A 35-year-old nonsmoker man presented complaining of productive and irritant cough for approximately 1 month. No history of fever, shortness of breath, weight loss, or other associated symptoms were present at admission. Physical examination, including careful evaluations of cardiovascular and respiratory systems, did not reveal any abnormalities. Past medical records (including allergies and occupational agent exposure) were also found to be unremarkable. A chest roentgenogram with frontal and lateral incidences and a blood sample analysis were therefore performed, but the reports of both these analyses were normal, demanding further imaging investigation.

A thoracic computed tomography (CT) showed a nodular hypodense mass, which partially obstructed the right main bronchus path (Figure 1). Region of interest CT tool was used to assess the very low-density nature of the lesion (Figure 2), suggesting the diagnosis of a lipomatous endobronchial neoplasm. A subsequent fibrobronchoscopy (Figure 3) confirmed the appearance of a 2-cm polypoid mass, smoothly covered by mucosal tissues, and a mild inflammation, determining locoregional airway sub-stenosis. Post-biopsy specimen analysis corroborated the predominance of fatty tissues surrounded by epithelial cells inside the tumor; this finding was consistent with an endobronchial lipoma.

Figure 1

(A) Axial computed tomography (CT) scan indicating the presence of a rounded circumscribed lesion (arrow) within the right main bronchus. (B) Coronal reformatting CT section corroborating the same finding (arrow), demonstrating its proximity to lobar bronchi emergences.

Figure 2

Applicability of region of interest (ROI) tool (circle), showing a mean density of -143 hounsfield units (HU), what highly suggested a lipomatous component inside the nodule.

Figure 3

Fiberoptic bronchoscopy photograph achieved before biopsy performance shows the obstructive character of the lesion, which was covered by mucosal tissue. Histological analysis revealed it to be an endobronchial lipoma.

Endobronchial lipomas are infrequent benign tumors, and usually originate from the submucosal layer of the main bronchus.1 However rare, their rounded morphology and benign appearance are resemblant of thoe of lipomas located elsewhere.2 Cross-sectional imaging modalities, such as chest CT, currently play a diagnostic role in most situations, because clinical presentation and physical examination features are largely nonspecific.2,3 In daily practice, CT features often provide sufficient information for proper management of such lesions when the therapy for all benign endobronchial neoplasm is very similar, mainly consisting of imaging-guided lesion’s excision or airway resection in exceptional situations.3 Nonetheless, the definitive diagnosis is only obtained after biopsy performance (generally through fiberoptic bronchoscopy) and histological analysis, which permanently phases out a nodule’s malignant potential and distinguishes true lipomas from endobronchial hamartomas in which cartilaginous components and calcifications are more likely to occur.2,3