Localized or diffuse lesions of the submandibular glands in immunoglobulin g4-related disease in association with differential organ involvement

Sonographic Features of Salivary Glands in Sjögren's Syndrome and its Mimics

PURPOSE OF REVIEW

For 30 years, ultrasound has been investigated as a means to evaluate salivary gland abnormalities in patients with autoimmune disease. We aim to review the test characteristics of ultrasound for diagnosing Sjögren's syndrome, the scoring systems used for this purpose, and the ultrasound similarities and differences between Sjögren's syndrome and some of its potential salivary gland mimics.

RECENT FINDINGS

Hypo/anechoic glandular lesions are the major ultrasound characteristic found in Sjögren's syndrome. Most studies have reported such ultrasound abnormalities to have a sensitivity and specificity in the range of 65-85% and 85-95%, respectively, as well as a positive likelihood ratio between 4 and 12. However, similar findings can also be seen in sarcoidosis, amyloidosis, IgG4-related disease, HIV, and lymphoma. A "nodal" pattern of involvement or the ultrasound artifact of "through transmission" can help distinguish some of these mimics from Sjogren's syndrome. Ultrasound can substantially influence the diagnosis of Sjögren's syndrome.

Sonographic diagnosis in the head and neck region: from an educational lecture presented at the 56th General Assembly and Annual Scientific Congress of the Japanese Society for Oral and Maxillofacial Radiology

Sonography is a simple, inexpensive, and non-invasive diagnostic modality. Although tissues behind bony structures and deep tissues are not delineated, sonography can depict superficial soft tissues very clearly. In the head and neck region, however, it has not yet been used widely, as the anatomical structures are complicated, and considerable experience is needed both to perform an examination and to make a diagnosis. To perform examinations efficiently, operators must be familiar with the sonographic system in use, and take images at standard planes. To make a correct diagnosis, operators require knowledge of the sonographic anatomy on standard planes, representative sonographic signs and artifacts, and common diseases and their typical sonographic findings. In this paper, we have explained the sonographic anatomy on standard planes, and the sonographic findings of common diseases in the oral and maxillofacial region.

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

IgG4-related disease is a relatively newly described entity with findings that historically have been confused with a variety of other diseases with markedly different treatments and prognoses, including Sjogren's syndrome and MALT lymphoma. We present a case of IgG4-related disease of the salivary glands and review the literature on sonographic findings of IgG4-related disease. By connecting sonographic features of IgG4 disease with common ancillary features of IgG4 disease in other sites (pancreas, hilar lymph nodes, biliary tree, thyroid, and retroperitoneum), radiologists can play a pivotal role in the early diagnosis and identification of IgG4-related disease. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 46:73-77, 2018.

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

INTRODUCTION

The 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).

METHODS

Thirty-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-[(18)F]-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.

RESULTS

On 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 (18)F-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.

CONCLUSIONS

Changes in the submandibular glands affected by IgG4-DS could be easily detected using sonography (characteristic bilateral nodal/reticular change) and FDG-PET/CT (abnormal (18)F-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.

Diagnostic Approach to the Complexity of IgG4-Related Disease

IgG4-related disease (IgG4-RD) is a systemic disease characterized by the infiltration of IgG4-bearing plasma cells and, more importantly, distinctive histopathological features: storiform fibrosis, obliterative phlebitis, a lymphoplasmacytic infiltrate, and mild-to-moderate tissue eosinophilia. The diagnostic approach is complex and relies on the coexistence of various clinical, laboratory, and histopathological findings, none of which is pathognomonic in and of itself. IgG4-related disease should be suspected in patients presenting with unexplained enlargement or swelling of 1 or more organs or tissue organs. Four laboratory abnormalities often provide initial clues to the diagnosis of IgG4-RD: peripheral eosinophilia, hypergammaglobulinemia, elevated serum IgE levels, and hypocomplementemia. Elevated serum IgG4 levels provided critical information in identifying the first cases of IgG4-RD, but recent studies have reported substantial limitations to the measurement of serum IgG4 concentrations, precluding reliance on serum IgG4 concentrations for diagnostic purposes. In contrast, new studies have suggested a promising role of flow cytometry studies in the diagnosis and longitudinal management of IgG4-RD. Demonstration of the classic histopathological features of IgG4-RD remains crucial to diagnosis in most cases, and biopsy proof is preferred strongly by most disease experts before the initiation of treatment. Of note, the multiorgan nature of IgG4-RD was first established in 2003. This review intends to provide most recent knowledge about the clinical, laboratory, radiological, and pathological characteristics of IgG4-RD that may guide the physician to establish an early diagnosis. We searched PubMed and MEDLINE for relevant articles published between January 1, 2000, and November 1, 2014, using the search terms IgG4 and IgG4-related.

Sonographic evaluation of the treatment response in patients with immunoglobulin G4-related disease of the submandibular glands

OBJECTIVES

To evaluate the usefulness of sonography for monitoring the response to glucocorticoid treatment in patients with immunoglobulin G4 (IgG4)-related disease.

METHODS

We conducted a retrospective study using sonography in 12 patients with bilateral swollen submandibular glands who had a diagnosis of IgG4-related disease based on an elevated serum IgG4 level (>135 mg/dL) and histopathologic findings between January 2010 and December 2012. Among these patients, 6 were treated with prednisolone, and the other 6 were placed under observation. B-mode sonographic examinations of the submandibular glands were performed with or without color Doppler imaging at the initial examination and 6 months later. Findings were compared between the groups (treated and untreated), and their relationship with the treatment response of the primarily involved organs was investigated.

RESULTS

In the treated group, the submandibular glands of all 6 patients decreased in both size and volume after treatment (average volume ± SD, 27,449.7 ± 24,227.6 to 4609.7 ± 1911.4 mm(3); P = .004). The internal echo texture, characterized by multiple hypoechoic foci scattered against a heterogeneous hyperechoic background of submandibular tissue with demarcated hyperechoic lines, with or without hypoechoic tumor formation, disappeared or was obscured in all cases. In addition, the blood flow signals were reduced in all 3 patients who underwent color Doppler sonography, and the response observed on sonography was found to correlate with the IgG4 level and recovery of specific organ involvement. In contrast, in the untreated group, the submandibular glands showed a tendency to increase in both size and volume (average volume, 9326.3 ± 3054.8 to 12,217.4 ± 4605.5 mm(3); P= .2) without a decrease in the blood flow signals.

CONCLUSIONS

Sonography is considered useful for evaluating the response to glucocorticoid therapy in patients with IgG4-related disease of the submandibular glands.

The clinical spectrum of IgG4-related disease

IgG4-related disease (IgG4-RD) is an emerging immune-mediated disease with the capability of involving essentially any organ. The epidemiology of this disease has not been explored in detail. A majority of patients reported in the literature to date are from Japan, but the condition has been described all across the world and there is no strong evidence to suggest a predilection for Asian populations. The mean age at diagnosis is approximately 60 years and there is a decided male predominance for many clinical features, with an overall male:female ratio of 8:3. A cardinal feature of IgG4-RD is single or multiple organ swelling that often raises concern for malignancy. IgG4-RD should be suspected in patients presenting with unexplained enlargement or swelling of one or more organs. Presenting features vary substantially according to the specialty to which patients present first; in addition, the disease can be diagnosed unexpectedly in pathological specimens or identified incidentally on radiology studies. Involvement of major organs is common and IgG4-RD may lead to organ failure, particularly in the pancreas, liver and biliary tree, kidneys, thyroid gland, lungs, and aorta. The diagnosis of IgG4-RD relies on the coexistence of various clinical, laboratory and histopathological findings, although none is pathognomonic by itself.