Immunoglobulin‐producing cells in plasma cell orificial mucositis

Plasma cell orificial mucositis is a benign idiopathic condition of orificial mucous membranes characterized histologically by a dense band-like plasmacytic infiltrate. We studied 8 cases of this disease by immunohistochemical methods for subsets of immunoglobulin-producing cells. The infiltrating plasma cells were found to produce mostly IgG and IgA with the predominance of kappa chain-producing cells over lambda chain-producing cells. This polyclonal plasma cell infiltrate composed of IgG- and IgA-producing cells is in accordance with the pattern observed in the inflammatory infiltrate around certain epidermal neoplasms accompanied by the plasmacytic infiltrate, such as actinic keratosis, Bowen's disease, squamous cell carcinoma, and syringocystadenoma papilliferum.