A Case Report of IgG4-related Disease With Common Clinical Manifestation in an Atypical Gender

Background IgG4-related disease (IgG4-RD) is a recently described clinicopathological condition with a wide range of clinical manifestations including a dense lymphoplasmacytic infiltrate rich in IgG4positive plasma cells, fibrosis arranged in a storiform pattern, obliterative phlebitis, and elevated serum IgG4 concentrations. Treatment involves corticosteroids and rituximab for the most severe cases. Methods Here we present two cases, two white females (aged 26 and 50 years) with IgG 4-RD, low back, flank pain and retroperitoneal mass, with a compressive effect on the kidney and ureter, and hydronephrosis. Biopsy of mass revealed infiltrates with IgG4 plasma cells, consistent with the diagnosis of IgG4-RD. The patients were treated with steroids and rituximab, and the results showed significant improvement. Conclusion Retroperitoneal fibrosis, a rare cause of back pain in young adults, should be suspected in patients with back pain, renal dysfunction, and other associated symptoms. It is important to identify this particular cause as it is treatable and may be easily missed. The diagnosis is done by kidney function assessment, abdominal computed tomography scan, or magnetic resonance imaging. Biopsy of the mass can help identify malignancy.