Effectiveness of imaging modalities for screening IgG4-related dacryoadenitis and sialadenitis (Mikulicz’s disease) and for differentiating it from Sjögren’s syndrome (SS), with an emphasis on sonography

Abstract

IntroductionThe aim of this study was to clarify the effectiveness of various imaging modalities and characteristic imaging features in the screening of IgG4-related dacryoadenitis and sialadenitis (IgG4-DS), and to show the differences in the imaging features between IgG4-DS and Sjögren’s syndrome (SS).MethodsThirty-nine patients with IgG4-DS, 51 with SS and 36 with normal salivary glands were enrolled. Images of the parotid and submandibular glands obtained using sonography, 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT), computed tomography (CT) and magnetic resonance imaging (MRI) were retrospectively analyzed. Six oral and maxillofacial radiologists randomly reviewed the arranged image sets under blinded conditions. Each observer scored the confidence rating regarding the presence of the characteristic imaging findings using a 5-grade rating system. After scoring various findings, diagnosis was made as normal, IgG4-DS or SS, considering all findings for each case.ResultsOn sonography, multiple hypoechoic areas and hyperechoic lines and/or spots in the parotid glands and obscuration of submandibular gland configuration were detected mainly in patients with SS (median scores 4, 4 and 3, respectively). Reticular and nodal patterns were observed primarily in patients with IgG4-DS (median score 5). FDG-PET/CT revealed a tendency for abnormal 18F-FDG accumulation and swelling of both the parotid and submandibular glands in patients with IgG4-DS, particularly in the submandibular glands. On MRI, SS had a high score regarding the findings of a salt-and-pepper appearance and/or multiple cystic areas in the parotid glands (median score 4.5). Sonography showed the highest values among the four imaging modalities for sensitivity, specificity and accuracy. There were significant differences between sonography and CT (p = 0.0001) and between sonography and FDG-PET/CT (p = 0.0058) concerning accuracy.ConclusionsChanges in the submandibular glands affected by IgG4-DS could be easily detected using sonography (characteristic bilateral nodal/reticular change) and FDG-PET/CT (abnormal 18F-FDG accumulation). Even inexperienced observers could detect these findings. In addition, sonography could also differentiate SS. Consequently, we recommend sonography as a modality for the screening of IgG4-DS, because it is easy to use, involves no radiation exposure and is an effective imaging modality.

Sonographic findings of IgG4‐related disease of the salivary glands: Case report and review of the literature

“…Three of the 10 articles described additional involvement of the lacrimal glands, with 4 articles also describing abdominal involvement (autoimmune pancreatitis, sclerosing cholangitis), although extrasalivary gland manifestations were not systematically described in all articles. Regarding sonographic features, 9 of the 10 articles (as well as our case) described hypoechoic lesions with variable descriptions of the pattern (reticular/nodal pattern, irregular, netlike appearance, heterogeneous echotexture, diffuse hypoechogenicity) with 5 of 10 describing enlargement of the submandibular gland(s) …”

“…Of the remaining 12 articles, 3 were duplicates. Review of these 9 articles found one additional article fulfilling inclusion criteria, leading to a final sample size of 10 articles …”

Chronic sclerosing sialadenitis (Küttner's tumor) of the submandibular salivary gland: Our experience of one case report

“…Ultrasound examination is a useful diagnostic tool and is initially used for the assessment of patients with enlarged salivary glands . Ultrasonography features show diffuse heterogeneous echogenicity with multiple hypoechogenic shadows, similar to liver cirrhosis .…”

“…Clinically, CSS may present with a firm, painless neck mass, which mimics a neoplastic process or a painful enlarged gland, such as in sialadenitis . Ultrasound features resemble those of a “cirrhotic liver” with diffuse involvement with multiple hypoechoic lesions against a heterogeneous background and duct dilatation . At CT, the lesions usually display like homogeneous attenuation and enhancement, and on MR imaging, the lesions typically demonstrate homogeneous low‐to‐intermediate signal intensity .…”

Immunoglobulin G4‐related disease and its skin manifestations

“…US findings in patients with IgG4-related Mikulicz disease show characteristic bilateral nodal and reticular patterns differentiating those from Sj€ ogren's syndrome. 31 Endoscopic US and intraductal US show concentric wall thickening of the distal common bile duct, causing the bile duct stenosis characteristic to untreated IgG4-related pancreatitis and the duct wall attenuating after steroid therapy. 32…”