IgG4-related disease in the abdomen and pelvis: atypical findings, pitfalls, and mimics

IgG4-Related Disease Manifesting as Hypocomplementemic Tubulointerstitial Nephritis: A Rare Case Report and Literature Review

“…Kidney involvement in IgG4-RD may manifest in several different ways, including ureteral obstruction from retroperitoneal fibrosis to the tubulointerstitial disease with plasma cell infiltration seen in this patient. 6 , 8 - 11 Patients with retroperitoneal fibrosis may complain of vague pain. 11 , 12 The patient in the case did complain of vague lower abdominal pain for several months prior to current presentation and reported gradual worsening of his lower abdominal pain that led to a diagnosis of retroperitoneal fibrosis on CT imaging, but there were no signs of hydronephrosis or obstructive uropathy.…”

“…6,8-11 Patients with retroperitoneal fibrosis may complain of vague pain. 11,12 The patient in the case did complain of vague lower abdominal pain for several months prior to current presentation and reported gradual worsening of his lower abdominal pain that led to a diagnosis of retroperitoneal fibrosis on CT imaging, but there were no signs of hydronephrosis or obstructive uropathy. Another way that the kidneys can become injured in IgG4-RD is from tubulointerstitial infiltration with IgG4-secreting plasma cells.…”

Imaging findings of immunoglobulin G4-related disease: from the head to the pelvis

“…(1) There are two subtypes of AIP based on pathological findings: Type 1, lymphoplasmacytic sclerosing pancreatitis and Type 2, idiopathic duct-centric chronic pancreatitis. (6,12) Type 1 is the pancreatic manifestation of IgG4-RD, whereas Type 2 has distinctly different histologic and clinical features without elevation of serum IgG4 or autoantibodies. (6,12) Patients may have abdominal pain, obstructive jaundice, weight loss or new-onset diabetes mellitus, and some patients have no symptoms.…”

“…(6,12) Type 1 is the pancreatic manifestation of IgG4-RD, whereas Type 2 has distinctly different histologic and clinical features without elevation of serum IgG4 or autoantibodies. (6,12) Patients may have abdominal pain, obstructive jaundice, weight loss or new-onset diabetes mellitus, and some patients have no symptoms. There are two imaging patterns of AIP: diffuse and focal.…”

“…(6) Diffuse type is the more common pattern that is characterised by a diffusely enlarged pancreas with the absence of normal lobulated contours, giving it a sausage-like appearance. (6,8,12) The affected area has a hypovascular appearance on arterial phase CT (Fig. 8a) and delayed enhancement.…”