Oral plasma cell mucositis: review of the literature

Background: Plasma Cell Mucositis is a rare, benign, chronic inflammatory disorder characterized by a dense subepithelial infiltrate of mature plasma cells in mucosal tissues. A rigorous diagnostic work-up is essential to distinguish oral plasma cell mucositis from plasma cell neoplasms and other clinically similar conditions, thereby guiding appropriate management. Case Scenario: A 66-year-old woman presented with a one-year history of recurrent intermittent burning sensation of the tongue, oral pain, mucosal irritation, and progressive swelling of the lips and gingiva. The tongue showed multiple erythematous, shiny papules and plaques at left lateral border and diffuse intense erythema of the oral mucosa. Regional lymph node were unremarkable. Direct immunofluorescence on perilesional tissue were negative. No history of autoimmune disease or other significant systemic illnesses. Routine laboratory investigations, complete blood count, comprehensive metabolic panel, serum immunoglobulin levels, and serum protein electrophoresis, were within normal limits. An incisional biopsy of tongue on histopathology showed hyperplastic stratified squamous mucosa. Subepithelial tissue with a dense polyclonal plasma cells infiltrate within the superficial lamina propria. Histopathological diagnosis of plasma cell mucositis was given. The patient was treated with systemic oral corticosteroid therapy, resulting in significant clinical improvement.Conclusion: Diagnosis of oral plasma cell mucositis can be challenging. It requires a multidisciplinary approach for exclusion of various benign and malignant conditions. A comprehensive review of literature shows that oral plasma cell mucositis is a rare, benign, chronic inflammatory disorder characterised by dense polyclonal plasma cell infiltrates in the lamina propria. Overall it showed a favourable prognosis and no significant complications.