The pancreatic and extrapancreatic manifestations of IgG4-related disease

The association between immunoglobulin IgG4 and autoimmune pancreatitis was first shown in 2001. Since then many previously established fibrosclerotic diseases demonstrating synchronous or metachronous multiorgan involvement have been included within the ambit of IgG4-related disease. Diagnostic criteria have been proposed involving 1) serum IgG4 level elevated beyond 135 mg/dL, 2) IgG4+ to IgG+ plasma cell ratio >40% and >10 IgG4+ cells per high power field of biopsy sample and 3) a constellation of imaging features which involve a variety of organ systems. We present a pictorial essay demonstrating the spectrum of imaging findings for IgG4-related disease, including dacryosialadenitis, variety of renal lesions, tumefactive thickening of the extraocular muscles and orbital nerve, sclerosing cholangitis, and type I pancreatitis. Imaging plays an important role in diagnosis, screening for multiorgan involvement, and follow-up of the disease. You may cite this article as: Sangha Brar JS, Gupta S, Haja Mohideen SM, Liauw L, Lath N. The pancreatic and extrapancreatic manifestations of IgG4-related disease. Diagn Interv Radiol 2018; 24:10.5152/dir.2018.17319. Diagnostic and Interventional Radiology Brar et al. The intraorbital findings of the IgG4-RD may include orbital inflammatory pseudotumor, which may present as unilateral or bilateral intraconal, conal, or extraconal masses, as shown in Fig. 2. Although inflammatory pseudotumor may be within the spectrum of IgG4-RD, most cases have a different etiology (4). Thickening of the cranial nerves may be encountered, with trigeminal nerve and its branches being the most commonly involved nerve (Figs. 3, 4). It presents as tubuMain points Diagnostic criteria for IgG4-related disease include: • Organ involvement: i. Dacryosialadenitis: swelling of two pairs of glands ii. Lungs: solid nodular, round-shaped ground glass opacities, alveolar interstitial, or bronchovascular lesions iii. Eyes: extraocular muscle and orbital nerve mass-like thickening iv. Kidneys: tubulointerstitial nephritis, cortical nodules, peripheral cortical lesions and renal pelvis involvement v. Sclerosing cholangitis (with response to steroid trial) vi. Type I pancreatitis (with response to steroid trial) vii. Others: retroperitoneal fibrosis, lymphadenopathy, sclerosing mesenteritis • Serum IgG4 >135 mg/dL • IgG4+ / IgG+ cell ratio >40% and >10 IgG+ cells per high power field of biopsy sample Figure 1. Axial T1-weighted contrast-enhanced MRI of the orbits showing asymmetric thickening and enhancement of the left lacrimal gland (left arrow). Incisional biopsy showed IgG4-related sclerosing dacroadenitis. Figure 2. CT image of the orbits shows symmetrical thickening and enhancement of bilateral lacrimal glands, one of which was biopsied later to reveal IgG4-RD (horizontal arrows). Figure 3. T1-weighted contrast-enhanced image of the brain shows thickening and enhancement of the left V1 (first branch of trigeminal nerve) (left arrow). Figure 4. T1-weighted contrast-enhanced image of the brain shows thickening and enhancement of the left infraorbital nerve (left arrow). Also note sinusitis in this patient (down arrow). Figure 5. Axial CT image shows right 2A cervical lymphadenopathy (lower arrow) with the submandibular gland pushed medially (upper arrow). Excision biopsy showed lymphoid hyperplasia with reactive plasmacytosis consistent with IgG4-RD. Figure 6. a–c. Axial (a) and coronal (b) CT images show thickening of the abdominal aortic wall with surrounding inflammatory changes in keeping with aortitis (left arrow). The image also shows thickening of the colonic wall with pericolic inflammatory fat stranding (down arrow). Also note thickening of the right proximal ureter walls (right arrow). Axial CT (c) through similar level after 3 months of corticosteroid therapy. Note decrease in aortic wall thickening, right ureter thickening, and resolution of bowel wall thickening and inflammation. a