8th Baltic Congress of Radiology

Thoracic Radiology

poster abstract

Aim of the report is to show a rare case of bronchial obstruction due to endobronchial lipoma. Benign tumors of lung and bronchi are uncommon. And according to literature, endobronchial lipoma (EL) is an extremely rare benign tumor with incidence 0,1 – 0,5 % of all lung tumors. Mostly, EL is single (one per patient) and located in the first three subdivisions of the bronchial tree, very rare in trachea. In literature, risk factors are smoking and obesity. EL originates from the fat cells, located in the peribronchial and the submucosal tissue. Clinical symptoms are caused by mechanical obstruction of the bronchus or due to secondary postobstructive infection – wheeze, dyspnea, hemoptysis, persistent cough, recurrent fever, chest pain, which may be present even for years. Rarely, some patients present with no symptoms and the EL is incidental finding. Large EL can cause full obstruction of bronchus, causing atelectasis and subsequent pneumonia, even irreversible lung damage. Chest computed tomography (CT) is highly sensitive for detection of fat tissue, so on the chest CT fat-density homogenous mass is seen inside the bronchus, without contrast enhancement. CT helps to localize the mass precisely, to evaluate the extent of tumor and to detect possible complications. Chest X-ray does not have specific signs of EL, however can show complications – atelectasis or pneumonia. EL can be managed by bronchoscopy or less commonly by surgical resection. The main differential diagnosis is lipomatous hamartoma, which may contain cartilage, fat, fibrous tissue, smooth muscle end epithelial cells.

Retrospective analysis of clinical case was performed. 61 y.o. male patient was admitted to Emergency Department of Riga East University Hospital because of suspected recurrent stroke. Head CT showed no signs of acute ischemia and patient was admitted to Department of Neurology. A routine chest X-Ray showed reduced pneumatization in the lower field of the right lung with differential between atelectasis or interlobar fluid. Chest CT showed right middle lobe (RML) atelectasis with bronchial mucocele. Patient denied any respiratory symptoms (cough, shortness of breath, thoracic pain etc.) and smoking. The bronchoscopy was performed and large, smooth, round-shaped mass inside the right middle lobe bronchus was found, spreading to intermediate bronchus, with full obstruction of the RML bronchus. As a result, pulmonary tumor was suspected. Patient was discharged from the hospital in stable condition with recommendation to be under the supervision of general practitioner and to follow on biopsy results. Biopsy showed no signs of malignancy, just inflammatory changes in bronchus mucous membrane. After 2 months patient was repeatedly admitted to Department of Pulmonology. Repeated chest CT was performed, which showed no dynamic changes comparing to previous CT. As before: bilateral lung emphysema, shrinked RML with multiple tubular, fluid-filled structures; mediastinum dislocation; inside the right middle lobe bronchus was seen well demarcated, smoothly contoured, fat-tissue density structure with small calcifications, without contrast enhancement, spreading to intermediate bronchus. No signs of specific pulmonary nodules or specific lymphadenopathy. Conclusion: RML endobronchial lipoma with bronchus obstruction, RML atelectasis and bronchial mucocele. Blood tests were performed to exclude hydatid infection, which showed negative result. Patient was discharged from hospital with recommendation to consult a thoracic surgeon to decide about possible operative therapy.

Patient was admitted to Paula Stradins University Hospital for elective operation. Two bronhoscopic surgeries were made within 1 month – extirpation of RML bronchus tumor, cryoablation and bronchial sanation. After first surgery histologic analysis of operated material showed lipomatous tumor inside the RML bronchus wall, defined as endobronchial lipoma. Histological examination after second surgery showed no signs of tumorous tissue. After 5 months control chest CT was made, which showed atelectasis of RML with varicose bronchiectasis without pathological content, the RML bronchus deformation, with no evidence of fat tissue inside the bronchus. The following control bronchoscopy was made, which showed deformation of RML bronchus and segmental bronchi, no signs of tumor tissue - just mucous membrane and fibrotic changes. The result of therapy was evaluated as radical.

Endobronchial lipoma is a benign tumor and a very rare cause of bronchial obstruction. Mostly, clinical presentation is due to recurrent lung infection, rarely the EL is incidental finding. In case of the full bronchial obstruction irreversible lung damage also is possible, as in our patient. Chest CT is highly-sensitive diagnostic method for detection of the EL and the post-obstructive complications. Chest CT also is used to evaluate the result of therapy and the extent of lung damage. Chest X-Ray is not specific in this case, but can show complications and indicates the necessity of further examinations. Histological examination is obligatory to exclude malignancy. EL can be managed by bronchoscopy or less commonly by surgical resection.

Aim of the report is to show a rare case of bronchial obstruction due to endobronchial lipoma (EL). In our case patient had an EL in the right middle lobe (RML) bronchus with bronchus obstruction, RML atelectasis and bronchial mucocele, which was found on chest CT. The diagnosis was confirmed on subsequent bronchoscopy and by histological examination. Two bronhoscopic surgeries were made to extirpate the tumor with radical result of therapy.

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