IgG4-related lung disease manifested as pneumonia in puerperium: a case report.

IgG4-related lung disease (IgG4-RLD) is recently emerging entity. Several reports concerned with the clinicopathologic feature have been described, but this disease in puerperium has not been reported previously. Here, we report a 24-year-old woman diagnosed as IgG4-RLD in puerperium, who developed dry cough, low fever and exertional dyspnea following the delivery. The inflammatory markers and pulmonary lesions of the patient suggested pneumonia. However, there was no improvement after antibiotic treatment. The infiltration of IgG4-positive lymphoplasmacytes was found in lung biopsy by video-assisted thoracic surgery (VATS). And the serum IgG4 level was high. The patient was effectively treated with corticosteroids. This unique case highlights the occurrence of IgG4-RLD in puerperium and underscores it should be taken into consideration as a possible differential diagnosis when dense lymphoplasmacytic infiltration was found in pulmonary consolidation in complex puerperal respiratory cases.