Application of sialography in diagnosis and differential diagnosis of IgG4-related sialadenitis.

OBJECTIVES

This study aimed to identify imaging features of IgG4-related sialadenitis (IgG4-RS) and differentiate it from Sjögren's syndrome (SS) and chronic obstructive parotid/submandibular sialadenitis (COP/COS).

STUDY

DESIGN

A retrospective analysis of sialographic findings was conducted on 40 IgG4-RS patients. Two radiologists blindly evaluated sialographic features, including ductal dilation, wall smoothness, duct interruption, acinar patterns, and glandular emptying. A comparative analysis with SS and COP/COS was also performed.

RESULTS

Sialograms of 40 IgG4-RS patients (82 glands), 61 SS patients (71 glands), and 69 COP/COS patients (95 glands) were analyzed. Sialographic findings were categorized into four types: Type I (diminished/interrupted ducts without dilation), Type II (diminished/interrupted ducts with dilation), Type III (dilated main/branch ducts), and Type IV (normal appearance). In IgG4-RS, Type I and III were predominant in parotid glands, while Type I was more frequent in submandibular glands. Type II was most common in SS, and Type III in COP/COS.

CONCLUSIONS

Sialography reveals distinct features in IgG4-RS, especially in submandibular glands, characterized by diminished or interrupted secondary and tertiary ducts without peripheral duct dilation, aiding differentiation from SS and COP/COS.