Plasma Cell Mucositis: A Case Report of an Uncommon Benign Disease ^†

Plasma cell mucositis (PCM) is an unusual plasma cell proliferative disorder of the upper aerodigestive tract. It is a rare disease and its etiology is not yet known, it is considered a benign condition of adults and there is no correlation in literature with the development of plasma cell neoplasm. Clinical features are an intensely erythematous mucosa with papillomatous, cobblestone, nodular, or velvety surface changes. Symptoms include dysphagia, oral pain and pharyngitis [1]. Generally, PCM patients have a previous history of autoimmune or immunologically mediated disease. Despite plasma cell mucositis often involves the oral and genital mucosa, there was no genital involvement in this circumstance. We described a case of PCM involving the tongue of a 43-year-old-woman, the patient was referred to the Oral Pathology at the Faculty of Dentistry, Magna Graecia University of Catanzaro, in August 2019. Her past medical history was unremarkable. She reported a burning sensation in her mouth and local dysgeusia on the tip and the right lingual border for 5 years (Figure 1). In the first place several diagnostic hypotheses were proposed, the most of them discarded for incompatibility with blood and laboratory tests. The patient underwent an incisional biopsy under local anesthesia. The specimen was stored in a tube containing formalin 10% and sent to a laboratory for histopathological analysis. Microscopically, a large area of ulceration of the coating epithelium subtended by dense plasma cell infiltrate was observed. The final histopathological diagnosis was “Plasmacytosis of the mucous membranes with restriction for the kappa chains”. This disease rarely manifests itself on the tongue, especially in young patients with no comorbidities. The management of PCM is mainly aimed at reducing the symptoms, in fact the patient was treated with systemic prednisone 50 mg/day [2]. Many therapeutic treatments are able to stabilize but are not able to induce a complete remission. PCM is considered an uncommon benign disorder with a favorable prognosis. It is important to differentiate the PCM disease from other neoplastic conditions in order to achieve a better clinical management of the patients.