Inflammatory pseudotumors of the kidney due to IgG4-related tubulointerstitial nephritis

The paper presents the case of a female patient who was admitted to our department because of prolonged febrile syndrome, altered general status and renal tumoral masses revealed by thoracic and abdominal CT. After thorough histological examination, including immunohistochemistry and in situ hybridization studies, we reached the diagnosis of renal pseudotumoral masses due to IgG4-related tubulointerstitial nephritis. The kidney is a distinct target organ affected by IgG4-related sclerosing disease, and the most frequent manifestation is tubulointerstitial nephritis. We described the clinical, imagistic and histopathological features of kidney and urological involvement in IgG4-related sclerosing disease, especially focusing on IgG4-related tubulointerstitial nephritis. This is a rare case of IgG4-related sclerosing disease without extrarenal features, excepting lumboaortic lymphadenopathy.