Ulcerated palatal tumour in association with elevated serum IgG4

Abstract

A generally healthy 66-year-old woman presented with a painless mass at the junction of the soft and hard palate, adjacent to the right maxillary third molar tooth (18) consistent with a draining abscess. Imaging showed a mass extending into the right maxillary antrum with a differential diagnosis of a salivary gland neoplasm or squamous cell carcinoma. There was no improvement with oral antibiotics. An incisional biopsy showed a dense infiltrate of predominantly plasma cells associated with fibrosis that showed no evidence of clonality. The mass was then excised with the tooth 18. Immunohistochemistry showed more than 70% of the plasma cells to be IgG4 positive. Her serum IgG4 level was elevated at 3.89 g/L (reference range 0.08–1.4 g/L). The patient has remained well with some asymptomatic abnormalities on her imaging studies but with no evidence of involvement of other organs. IgG4 related disease is an increasingly recognised entity characterised by a variety of clinical manifestations with the common features being an elevated serum IgG4 and infiltration of tissue by IgG4 positive plasma cells causing a tumour-like swelling which is accompanied by variable degrees of fibrosis. IgG4 related disease is of unknown aetiology and can involve many tissues. The majority of patients respond to treatment with glucocorticoids.