IgG4-Related Disease of the Gastrointestinal Tract: A 21st Century Chameleon

Abstract

Context Immunoglobulin G4 (IgG4)–related disease is a systemic fibroinflammatory disease capable of affecting virtually any organ. Although the pancreas and hepatobiliary system are commonly affected, involvement of the tubular gut is unusual. The pancreatic manifestations of this disease (autoimmune pancreatitis) often mimic pancreatic carcinoma, whereas the hepatobiliary manifestations are mistaken for cholangiocarcinoma or primary sclerosing cholangitis. The characteristic histologic features include a dense lymphoplasmacytic infiltrate, storiform-type fibrosis, and obliterative phlebitis. An increase in IgG4+ plasma cells and an IgG4 to IgG ratio of more than 40% are considered obligatory components of the diagnostic algorithm. Objective To review the challenges associated with the diagnosis of IgG4-related disease of the gastrointestinal tract. Data Sources A review of pertinent literature, along with the author's personal experience, based on institutional and consultation materials. Conclusion The complete spectrum of histologic changes is seldom captured in a biopsy specimen, and thus, the histopathology findings are best interpreted within the overall clinical context. Increased IgG4+ plasma cells are identified in a variety of benign and malignant diseases of the gastrointestinal tract.

Immunoglobulin G4–related disease mimicking an epidural spinal cord tumor: case report

“…15 IgG4-RD often affects multiple organ systems, most typically causing sialadenitis, pancreatitis, and/or lymphadenopathy. 6,16,26 Common findings in IgG4-RD include an elevated serum IgG4 level (with a ratio of IgG4/IgG greater than 40%), infiltration of organs with IgG4-positive plasma cells, and fibrosis of the affected organs. 6,7,16 In the presented case, the patient’s IgG4 IHC staining was on the lower end of the results reported in other cases affecting the CNS, at 10 cells/hpf.…”

“…6,16,26 Common findings in IgG4-RD include an elevated serum IgG4 level (with a ratio of IgG4/IgG greater than 40%), infiltration of organs with IgG4-positive plasma cells, and fibrosis of the affected organs. 6,7,16 In the presented case, the patient’s IgG4 IHC staining was on the lower end of the results reported in other cases affecting the CNS, at 10 cells/hpf. However, given her overall clinical picture (negative workup for malignancy, histopathological results consistent with IgG4-RD, positive IgG4 IHC staining, and an excellent response to steroids), we are confident in the diagnosis of IgG4-RD.…”

“…Given that lesions caused by IgG4-RD are almost always responsive to steroid treatment, physicians must keep the condition in mind when evaluating a possibly malignant lesion. Though there are case reports of IgG4-RD in every area of the body, 1,4,6,7,9,13–14,16,18,21–23,26 involvement of the central nervous system (CNS) is quite rare. Here, we present a case of IgG4-RD manifesting as a cervical paraspinal mass that responded well to steroid treatment.…”

An Unexpected IgG4-Related Enteropathy Masquerading as a Stricturing Malignancy

“…While there are many reports of IgG4 related sclerosing mesenteritis, IgG4 related disease involving the lower tubular gut is generally met with scepticism. 7 A proposed explanation for this rare phenomenon is that the disease originates in the mesentery and then spreads to the bowel wall.…”

Immunoglobulin G4-Related Disease Manifesting as Isolated, Typical, and Nontypical Gastroesophageal Lesion: A Research of Literature Review

“…IgG4-RD can affect multiple organs simultaneously or can present as a solitary, mass-like lesion [2]. The pancreas "autoimmune pancreatitis" (AIP), hepatobiliary system, retroperitoneum, aorta, kidney, orbit, lungs, lymph nodes, and salivary glands are the most commonly affected organs, although, the manifestation of the upper gastrointestinal tract is relatively rare [2,[6][7][8][9].…”