Immunoglobulin G4-related disease (IgG4-RD) is a multisystemic fibro-inflammatory condition characterized by tumefactive lesions, dense lymphoplasmacytic infiltrate, storiform fibrosis and obliterative phlebitis. Serum IgG4 levels are usually elevated in 70–90% of cases. The mean age at diagnosis is 60 years with a striking male preponderance. (Male:Female – 8:3)
Objectives To present a single center experience with IgG4-RD and the diagnostic and therapeutic challenges encountered.
Methods A retrospective case review at an urban teaching hospital was done over a year after the availability of quantitative assessment of IgG4 levels and tissue immuno-histological staining techniques. This revealed four cases of IgG4-RD involving the pancreas, retroperitoneum, kidney and meninges demonstrating its multi-systemic nature.
Results We encountered a M:F ratio of 3:1 with mean age at presentation being 66 year
Case 1: A 76-year-old male with significant weight loss, erroneously diagnosed with pancreatic tail malignancy, underwent distal pancreatectomy and was subsequently diagnosed with AIP on biopsy.
Case 2: A 71-year-old male s/p left partial nephrectomy 4 years ago with an incidental finding of right kidney mass (2x2x2cm). After undergoing right partial nephrectomy, he was diagnosed with IgG4-related kidney disease.
Case 3: A 56-year-old male with abdominal pain and worsening renal function had MRI findings of a heterogeneous retroperitoneal mass attached to the right kidney. Biopsy revealed a diagnosis of IgG4-retroperitoneal fibrosis.
Case 4: A 57-year-old female presented with headache, bilateral lower extremity weakness and gait abnormality. Elevated serum IgG4, leptomeningeal enhancement on MRI and dural biopsy all suggested IgG4-related pacchymeningitis.
Conclusions IgG4-RD often presents as a diagnostic conundrum. There is a need to increase clinician awareness of IgG4-RD, since early identification and subsequent treatment with immunomodulators may prevent disease progression and prevent complications and/or unnecessary surgeries. PET/CT may prove to be a useful adjunctive imaging technique to investigate for multi-system involvement. Over reliance on serum IgG4 levels for screening may result in missed diagnosis in a significant percentage of patients.
Disclosure of Interest None declared