We report a case of plasma cell gingivitis (PCG), which is a chronic inflammatory disorder, histologically characterized by dense plasma cell infiltration in the mucosa. The patient was a 55-year-old woman who presented with well-circumscribed redness associated with diffuse edematous swelling of the maxillary and mandibular anterior-tooth gingiva in December 2010. A second biopsy showed dense inflammatory cell infiltration, including mainly plasma cells, with no atypical cells. Immunohistochemically, these cells were positive for immunoglobulin kappa and lambda light chains. On the basis of the clinical and histopathological findings, the lesion was diagnosed as PCG. The patient was treated with a topical steroid containing antibiotics, and the lesion disappeared 6 months after starting treatment. No recurrence has occurred during 3 years of follow-up.
