IgG4-related disease: a case report and review of cases reported in China.

IgG4-related inflammatory pseudotumors are lesions characterized by plasma cell-rich histologic pattern, abundant IgG4-positive plasma cells and high serum IgG4 levels. A 64-year-old man was admitted to our hospital for an ultrasound-documented space-occupying lesion of the left kidney. Renal tumor of the left kidney was suspected based upon results of computed tomography and nuclear magnetic resonance, and laparoscopic radical nephrectomy was conducted. The final diagnosis of IgG4-related inflammatory pseudotumor was made based on histopathological examination and IgG4 immunostaining. The patient received steroid therapy. To our knowledge, this is the first case of IgG4-related inflammatory pseudotumor of the kidney reported in China.