The “great imitator”: IgG4‐related disease of the oral cavity. Two case reports and scoping review

Abstract

AbstractThis study aimed to review the lesser‐known intraoral manifestations of immunoglobulin G4‐related disease (IgG4‐RD). In this paper we report an unprecedented case of oral IgG4‐RD mimicking angiolymphoid hyperplasia with eosinophilia (ALHE), and another case presenting as plasma cell gingivitis. We then performed a scoping review of published cases of IgG4‐RD involving the oral cavity. The following data were collected for each case: age, sex, intraoral site(s) involved, clinical appearance, imaging features, serum IgG4 values, histopathology, treatment, and follow‐up duration. Fifty‐one cases of oral IgG4‐RD were published in literature. The hard palate and jaw bones were the two main locations reported, while the histological identification of a IgG4/IgG plasma cells ratio ≥40% was fundamental for diagnosis. Conversely, the pathological features of storiform fibrosis and obliterative phlebitis were not common. Future reports regarding oral IgG4‐RD should report clear adherence to the recognized international diagnostic criteria of the disease.