IgG₄-related disease: an atypical presentation of steroid-responsive renal mass

Abstract

IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disease characterised by dense lymphoplasmacytic infiltration rich in IgG4-positive plasma cells, storiform fibrosis and obliterative phlebitis. Serum IgG4 levels are typically elevated but half of the patients had normal serum IgG4 levels. IgG4-RD represents a spectrum of diseases that involve various organs such as the pancreas, liver, kidneys, and salivary glands often manifesting as diffuse organ enlargement or a mass-like lesion mimicking cancer. An increased incidence of malignancy among patients with IgG4-RD has been reported. Thus, differentiating malignancy from IgG4-RD manifestation is important as the treatment differs. Glucocorticoids are considered first-line therapy and should be started early to prevent fibrosis. Patients usually have an excellent clinical response to steroids, and poor steroid response is indicative of an alternative diagnoses such as malignancy. This case report describes a case of IgG4-RD with renal mass in a young man that resolved with glucocorticoid therapy alone.

Immunoglobulin G4-Negative Inflammatory Pseudotumors of the Pancreas

“…Since pancreatic resection portends significant morbidity and possible mortality to the patients, some authors reported their experience of observation with non-operative therapies resulting in regression. Nonsteroidal anti-inflammatory medications and corticosteroids have been previously used to treat IPTs for palliation [ 9 , 32 , 36 ] or to make the mass a more resectable size and configuration [ 6 , 12 , 19 , 37 , 38 ] in confirmed cases of IPTs. While rare, spontaneous regression of lesions has been reported [ 2 , 19 , 39 - 41 ].…”