Refractory IgG4-related Pleural Disease with Chylothorax: A Case Report and Literature Review

Abstract

We herein report a rare case of a 66-year-old man with refractory chylothorax. Although he had been treated with moderate doses of prednisolone (PSL) on suspicion of pleuritis with Sjögren syndrome, the pleural effusion expanded after the reduction of PSL. Further workup including histopathological examinations of pleura led to the diagnosis of IgG4-RD with bilateral chylothorax without any leakage from the thoracic duct. Combination therapy with high-dose PSL plus rituximab successfully decreased the pleural effusion. This is a very rare case of IgG4-related pleuritis with chylothorax and the first report of its successful treatment with rituximab.

Keywords: IgG4-related disease; chylothorax; pleuritis; rituximab.

Figure 1.

Pleural effusion and CT images before and after treatment. The right pleural effusion appeared as turbid yellow fluid (A). Bilateral pleural effusion and pericardial effusion were seen at the second admission (B). After treatment with a combination of high-dose corticosteroids and rituximab, the pleural and pericardial effusion was significantly decreased (C).

Figure 2.

Lymphangiography images. Lymphangiography showed the intact structure of the thoracic duct (yellow arrows) and revealed no leakage or obstruction of the duct.

Figure 3.

Histopathological images from the pleural biopsy. A pleural biopsy showed the infiltration of lymphocytes and plasma cells with ectopic germinal centers under the pleural mesothelium, and more than 50% of IgG-positive plasma cells were IgG4-positive. HE: Hematoxylin and Eosin staining, LPF: low-power field, HPF: high-power field

Figure 4.

Histopathological images from the lip biopsy. A lip biopsy revealed focal IgG4-positive plasma cell infiltration, with up to 48 cells/HPF and an IgG4/IgG ratio exceeding 50%. HE: Hematoxylin and Eosin staining, LPF: low-power field, HPF: high-power field

Figure 5.

Summary of clinical course of this patient. The pleuritis showed an insufficient response to the first induction therapy with moderate-dose PSL and diuretics. However, the second induction therapy with high-dose PSL and RTX resulted in the significant improvement of pleuritis and a reduction in the serum IgG4 levels. PSL: prednisolone, mPSL: methylprednisolone, RTX: rituximab, Tx: treatment