PMC6434167_01
Radiological findings. (A, B): Chest computed tomography (CT) at the initial consultation revealed tracheobronchial stenosis at the introitus of the middle lobar branch. (C): 18F-fluorodexyglucose-positron emission tomography (18FDG-PET) showed a hot spot in the right middle lobe bronchus.
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He underwent 18F-fluorodeoxyglucose (FDG)-positron emission tomograghy (PET)/CT, which showed a mild FDG uptake (standardized uptake value [SUV] max 4.60) within the introitus of the right middle lobe bronchus but no other findings (Fig. 1C).
Bronchoscopic findings in July 2018 (A-C) and after one month (D-F). (A, B). Bronchoscopic view showing several endobronchial nodular protrusions along the right middle bronchus. (C) The extent of the tumor margin was clearly identified as a magenta image by an autofluorescene imaging bronchovideoscope system (AFI). (D-F) Bronchoscopic findings after one month revealing the lesion had regressed, and the mucosal surface appeared regular with normal vessel translucency.
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B). Bronchoscopy showed several endobronchial nodular protrusions and bronchial thickening along the right middle bronchus (Fig. 2A and B). The extent of the tumor margin was clearly identified as a magenta image by an autofluorescene imaging bronchovideoscope system (Fig. 2C). Bronchoscopy was performed again to obtain sufficient material to confirm the pathological diagnosis, and the endobronchial lesions were found to have regressed while the mucosal surface appeared relatively regular without atrophy or stenosis. (Fig. 2D-F).
The resected segment of the right middle lobar branch and right middle lobe contained a smooth-surfaced, nodular mass, 10 x 5 mm in diameter, without any other findings in the right middle lobe. The lesions were localized to the right middle lobar branch.
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Regarding macroscopic findings, a protruded lesion (10 x 5 mm) was seen at the introitus of the middle lobar branch (Fig. 3).
Pathological findings. A, B: Light microscopic image showing infiltration of small-to medium-sized lymphoid cells into the epithelium (Hematoxylin and Eosin staining; 10x, 100x magnification). C: CD20 staining of the cells was positive, indicating a B-cell origin (CD20 staining; 200x magnification). D: Lymphoepithelial lesions were identified (cytokeratin [AE1/AE3] staining; 200x magnification).
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A pathological examination showed the diffuse infiltrate of small-to medium-sized lymphoid cells in the mucosa (Fig. 4A and B). The lymphoid cells were positive for CD20 and negative for cytokeratin (AE1/AE3) (Fig. 4C and D).