Immunoglobulin G4-related disease of the hard palate.

A 71-year-old woman presented with erythematous, nontender, bilateral hard palate nodules of 6-month duration. Biopsy showed collagenous sclerosis and a follicular lymphoplasmacytic infiltrate among the minor salivary glands. Immunoglobulin G (IgG) and IgG4 staining showed 280 IgG4(+) cells per high-power field and a ratio of IgG4(+) to IgG(+) cells of 0.8. The patient subsequently developed bilateral lacrimal gland and parotid gland enlargement associated with an increased serum IgG4 level of 3,031 mg/dL (≤ 135 mg/dL). Left lacrimal gland biopsy confirmed IgG4-related dacryoadenitis. The patient declined corticosteroid treatment for IgG4-related disease (IgG4-RD) and remained stable at 15 months after the first presentation. Spontaneous, partial resolution of the palatal lesion was observed during follow-up. IgG4-RD should be considered in the differential diagnosis of lymphoplasmacytic lesions of the hard palate.