case_images: PMC10715397_01
case_images: Chest CT on admission: there are patchy lesions observed in the upper lobe of the right lung, in conjunction with a right-sided pleural effusion accompanied by pleural thickening.
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case_images: fig1
case_images: A chest CT revealed patchy lesions in the upper lobe of the right lung, as well as a right pleural effusion with pleural thickening (Figure 1).
case_images: Thoracoscopic findings: parietal pleural hyperemia and white fibrotic plaque.
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case_images: PMC10715397_01_fmed-10-1247884-g002.jpg
case_images: fig2
case_images: Video-assisted thoracoscopic surgery was subsequently performed (Figure 2) and histological examination of pleural specimen showed lymphoplasmacytic infiltrates accompanied by fibrous tissue hyperplasia.
case_images: Histopathological evaluation of the pleura: (A) Hematoxylin and eosin staining (HEx200), (B) HE (x400): the right parietal pleural biopsy specimen reveals the presence of lymphoplasmacytic and plasma cell infiltration. (C) IgG4 immunohistochemical staining (x200), (D) IgG4 immunohistochemical staining (x400): the number of IgG4-positive plasma cells was 20/high-power field (HPF), and an IgG4/IgG ratio of 40-50%.
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case_images: fig3
case_images: Immunohistochemical staining revealed the presence of IgG4-positive plasma cells [20/high-power field (HPF)], with a high IgG4/IgG ratio of 40-50% (Figure 3).
case_images: Chest CT after treatment: patchy lesions and pleural effusion in the right lung almost disappeared.
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case_images: fig4
case_images: The patient was commenced on prednisone 40 mg daily and a follow-up CT 2 weeks later showed significant improvement with almost complete resolution of the lung lesions and pleural effusion (Figure 4).