Malignant Mesothelioma Diagnosed by Bronchoscopic Biopsy

Abstract

Malignant mesothelioma is a rare malignant neoplasm that arises from mesothelial surfaces of the pleural cavity, peritoneal cavity, tunica vaginalis, or pericardium. Typically, pleural fluid cytology or closed pleural biopsy, surgical intervention (video thoracoscopic biopsy or open thoracotomy) is conducted to obtain pleural tissue specimens. However, endobronchial lesions are rarely seen and cases diagnosed from bronchoscopic biopsy are also rarely reported. We reported the case of a 77-year-old male who was diagnosed as malignant mesothelioma on bronchoscopic biopsy from obstructing masses of the endobronchial lesion.

Keywords: Biopsy; Bronchoscopy; Mesothelioma, Malignant.

Figure 1. Large amount of pleural effusion with passive collapse of right middle lobe and right lower lobe on chest radiography (A) and peribronchial soft tissue thickening in right middle lobe and right lower lobe on chest computed tomography (B, C).

Figure 2. Positron emission tomography computed tomography showed multiple high uptake lesions (A-C), and bronchoscopic biopsy was obtained from anterobasal segment of right lower lobe (D-F).

Figure 3. (A-D) Initial bronchoscopic biopsy findings of papillary clusters of epithelioid cells, and positive staining with anti-calretinin antibody, cytokeratin 5/6, and Wilms tumor 1 stain in most of the neoplastic cells. (E-H) Pleural biopsy findings of neoplastic cells positive for anti-calretinin antibody, and cytokeratin 5/6, and definitive Wilms tumor 1. (I-L) Follow-up bronchoscopic biopsy findings of neoplastic cells positive for anti-calretinin antibody, and negative for p63, Wilms tumor 1 stain.

Figure 4. After 4 cycles of chemotherapy, decreased pleural effusion on chest radiography (A) and decreased peribronchial soft tissue thickening and pleural nodules in right middle lobe and right lower lobe were observed (B, C).