Paraneoplastic Pemphigus Associated with Follicular Lymphoma, Sjögren’s Syndrome, and Bronchiolitis Obliterans: A Case of Prolonged Survival

Introduction: Paraneoplastic pemphigus (PNP), also known as paraneoplastic autoimmune multiorgan syndrome, is a rare and often fatal autoimmune blistering disease associated with hematological malignancies. It is frequently complicated by severe extracutaneous manifestations such as bronchiolitis obliterans. Case Presentation: A 67-year-old woman presented with refractory, painful oral erosions and lichenoid skin lesions. Histopathological examination, direct immunofluorescence, and immunoblotting revealed findings consistent with PNP, including antibodies against envoplakin and periplakin. Further evaluation revealed concurrent follicular lymphoma, Sjögren’s syndrome, and bronchiolitis obliterans. Combination therapy with systemic corticosteroids and rituximab-based chemotherapy achieved remission of the lymphoma and sustained control of mucocutaneous lesions. The patient survived for 34 months after initial presentation despite progressive respiratory impairment. Conclusion: This case highlights the diagnostic complexity of PNP with overlapping autoimmune features and underscores the importance of early recognition and multidisciplinary management. Despite its typically poor prognosis, rituximab-based therapy may improve survival outcomes by targeting both the underlying malignancy and autoimmune activity.