Čes. stomatol. Prakt. zub. lék. (Czech Dental Journal) 2026; 126(3): 71-78 | DOI: 10.51479/cspzl.2026.003

DIAGNOSTIC COMPLEXITIES IN A SUSPECTED CASE OF IgG4-RELATED SIALADENITIS

Dehghan M.^{1, 2}, Laco J.^{3, 4}, Abou Assaf W.^{1, 2}, Bradna P.^{5, 6}, Tuček L.^{1, 2}

¹ Department of Dentistry, Faculty of Medicine in Hradec Králové, Charles University, Hradec Králové, Czech Republic

² Department of Dentistry, University Hospital Hradec Králové, Czech Republic

³ The Fingerland Department of Pathology, Faculty of Medicine in Hradec Králové, Charles University, Hradec Králové, Czech Republic

⁴ The Fingerland Department of Pathology, University Hospital Hradec Králové, Czech Republic

⁵ 2nd Department of Internal Medicine – Gastroenterology, University Hospital Hradec Králové, Czech Republic

⁶ 2nd Department of Internal Medicine – Gastroenterology, Faculty of Medicine in Hradec Králové, Charles University, Hradec Králové, Czech Republic

Introduction and aim: IgG4-related disease is an immune-mediated fibroinflammatory condition that may affect the salivary glands and mimic other chronic inflammatory disorders, making diagnosis challenging. We report a diagnostically complex case of suspected IgG4-related sialadenitis.
Case description: We present the case of a 41-year-old man with Graves-Basedow disease who developed persistent right-sided submandibular gland enlargement and cervical pain after a dental intervention. Serological testing showed that IgG4 accounted for 5.5% of total IgG, and imaging revealed diffuse enlargement of the right submandibular gland. Histopathological examination demonstrated chronic sialadenitis with acute exacerbation, fibrosis, and lymphoplasmacytic infiltration. No convincing obliterative phlebitis was identified. Immunohistochemistry demonstrated up to 30 IgG4-positive plasma cells per high-power field and an IgG4/IgG ratio of approximately 35–40%.

Conclusion: Although the findings raised suspicion for IgG4-related disease, established diagnostic thresholds were not fully met. This case highlights the overlap between chronic inflammatory sialadenitis and IgG4-related disease, particularly in a patient with autoimmune comorbidity, and emphasizes the importance of careful clinicopathological correlation and multidisciplinary follow-up.

Keywords: IgG4-related disease, chronic sialadenitis, submandibular gland, histopathology, differential diagnosis

Received: January 26, 2026; Revised: April 27, 2026; Accepted: May 16, 2026; Prepublished online: August 26, 2026; Published: September 7, 2026  Show citation