A245 IGG4- RELATED DISEASE AS A RARE CAUSE OF GASTRIC OUTLET OBSTRUCTION: A CASE REPORT AND LITERATURE REVIEW

Abstract

Abstract Background IgG4- related disease (IgG4-RD) is a newly recognized systemic fibroinflammatory condition that can affect a wide range of organs, including the pancreas, biliary system, retroperitoneum, lymph nodes and salivary glands. However, gastrointestinal luminal involvement is very rare, and the presentation with isolated gastrointestinal obstruction is extremely unusual. Aims We present a case of IgG4-RD presenting with gastric outlet obstruction secondary to severe duodenal stricture. Methods A 59-year-old female presented with 6 months history of abdominal pain, postprandial nausea and vomiting associated with significant weight loss. CT showed circumferential wall thickening of the 2ndand 3rd parts of the duodenum with gastroscopy showing severe ulcerated duodenal stricture that could not be passed through. Biopsies from the ulcerated area did not reveal a specific etiology, but malignancy could not be excluded, and the decision was made to pursue surgical management with Whipple’s procedure. Surgical pathology revealed IgG4 related disease in the form of an ulcerated gastric mass invading the duodenum and the pancreas with normal serum IgG4 level. Postoperatively, the patient developed anastomotic leak that was managed conservatively with antibiotics and drainage resulting in significant improvement in her symptoms. MRCP did not show any pancreatic or biliary abnormalities. Results A few weeks later, she represented with abdominal pain as well as nausea and vomiting. CT scan revealed severe inflammatory changes at the anastomosis site with mucosal thickening concerning for persistent leak. However, as she was optimally treated before, it was concluded that these changes are likely related to recurrent IgG4-RD. To induce remission, prednisone was started with remarkable improvement in her symptoms within two weeks, and complete resolution of the previous inflammatory changes around the anastomosis on repeat imaging. Subsequently, she was started on mycophenolate mofetil (MMF) with a slow prednisone taper. Conclusions IgG4-RD involving the gastrointestinal tract is rare with rare cases reported in the literature presenting in variable ways. Our case demonstrates the possibility of IgG4-RD presenting as gastric outlet obstruction; IgG4-RD should be considered in the differential diagnosis of unexplained duodenal stricture or gastric outlet obstruction. IgG4-RD usually responds to steroids but long-term response rates to steroid-sparing agents, especially in the subset of patients with luminal IgG4-RD, remains to be seen. Funding Agencies None