CPC05: Plasma cell mucositis: a complex and challenging condition

Majella Gregory,¹ Anisah Soobraty,² Paul Yesudian¹ and Anne Field¹

¹Royal Liverpool University Dental Hospital, Liverpool, UK; and ²Royal Liverpool University Hospital, Liverpool, UK

A 40-year-old man was referred to the Oral Medicine Department for a burning mouth. He had recently been diagnosed with subcorneal pustular dermatosis and had developed significant cervical lymphadenopathy, which was under investigation by Haematology and Oral & Maxillofacial Surgery. The patient reported a 10-month history of burning sensation in his mouth, in addition to oral ulceration. Clinical examination revealed widespread cervical lymphadenopathy. Oedema of the right and left buccal mucosae, with fissuring of the posterior right buccal mucosa and tongue were observed. There were signs of healing oral ulceration, and mild desquamative gingivitis and slight lip swelling were also observed. The differential diagnosis included orofacial granulomatosis and plasma cell mucositis. Biopsies of the right side of the tongue and right buccal mucosa showed active mucositis, and subsequent biopsy of a granulomatous lesion that the patient developed on his right tongue had an appearance consistent with plasma cell mucositis. An excisional biopsy of a left level III node neck was originally reported, in keeping with lymphoma, but subsequently re-reported as reactive. Lymphoma screening investigations were normal. Significant findings revealed positive anti-Ro antibody, positive hepatitis B virus core antibody, raised IgG and normal serum IgG4 levels. The patient later reported swallowing issues, and nasal crusting of blood was noted. Otorhinolaryngology confirmed inflammation of the pharyngeal and nasal mucosae. The oral lesions were initially treated with topical benzydamine, triamcinolone and nystatin. A reducing course of oral prednisolone failed to give much benefit. Plasma cell mucositis is a rare, benign plasma cell proliferative disorder of the mucous membranes. It is of unknown aetiology and can affect the oesophagus, nasopharynx, oropharynx, hypopharynx, larynx and nasal mucosa, as well as the oral cavity. It is usually chronic, and symptoms can include persistent hoarseness, sore throat, dysphagia and chronic cough, in addition to oral pain. It is important to differentiate this condition from extramedullary plasmacytoma and plasma cell gingivitis, which can also affect the oral cavity. The clinical appearance can be very varied and may include florid erythematous mucosa often with nodular or cobblestone surface changes. Papillomatous, velvety or granular changes may also be present. Erythema and swelling of the attached gingiva can also occur. Management of plasma cell mucositis lacks consensus, with many cases resistant to treatment. Usually aimed at achieving symptomatic relief, management can range from topical and systemic steroids to immunosuppressants, including dapsone, methotrexate and mycophenolate mofetil, among others. Surgical intervention is occasionally indicated to treat associated complications such as tracheal strictures. This reported case of plasma cell mucositis, with a wide range of clinical presentations illustrates the diagnostic and management challenges requiring multidisciplinary input across many specialties.