Paraneoplastic pemphigus associated with a malignant thymoma: A case of persistent and refractory oral ulcerations following thymectomy

Paraneoplastic pemphigus is a rare, life-threatening autoimmune mucocutaneous blistering disease associated with underlying neoplasia, commonly lymphoproliferative tumors. Herein we report a case of paraneoplastic pemphigus with a unique autoantibody profile associated with a malignant thymoma. A 56-year-old female patient presented with relapsing oral ulcerations accompanied by erythematous papules and patches on her extremities for 2 months. Skin and mucosal biopsies identified interface dermatitis with lichenoid lymphocytic infiltration in the upper dermis. Immunoblotting and enzyme-linked immunosorbent assays revealed that the patient had multiple autoantibodies against desmoglein 1, desmocollin 1, 2, 3, laminin gamma-1, envoplakin, and periplakin. The skin lesions completely healed following thymectomy and systemic corticosteroid therapy, but the oral ulcerations persisted through a follow-up period of over 2 years.