Clinicopathologic similarities between Mikulicz disease and Küttner tumor

PurposeRecent studies have revealed that Mikulicz disease (MD) differs from Sjögren syndrome and is an immunoglobulin G4 (IgG4)–related systemic disease. Küttner tumor (KT) is also reported to be an IgG4-related disease. In this study, we examined the clinicopathologic and serologic findings in MD (39 patients) and KT (6 patients) and attempted to discern the similarities between MD and KT.Materials and methodsWe diagnosed 39 patients with MD and 6 patients with KT. We analyzed the clinicopathologic and serologic findings (IgG subclasses) in 39 patients with MD and 6 patients with KT. Submandibular and labial salivary gland specimens obtained from patients with MD and KT were stained with anti-IgG4 antibodies.ResultsThe mean IgG4 concentration (±SD) was 931.1 ± 796.2 mg/dL in patients with MD and 756.2 ± 449.2 mg/dL in patients with KT. Abundant infiltration of IgG4-positive plasmacytes into the salivary glands was observed in both patients with MD and patients with KT.ConclusionThe serologic and histopathologic findings in MD and KT are very similar, and these 2 conditions may be IgG4-related systemic diseases.