Rituximab Monotherapy and Rituximab-Containing Chemotherapy Were Effective for Paraneoplastic Pemphigus Accompanying Follicular Lymphoma, but not for Subsequent Bronchiolitis Obliterans

A 60-year-old male patient suffered from mild exertional dyspnea, wheezing, and systemic blisters. He was diagnosed with paraneoplastic pemphigus (PNP) with follicular lymphoma in the pancreas head and pelvic cavity. He was first treated with eight cycles of rituximab; his blisters and erosions gradually improved and highly elevated levels of auto-antibodies related to PNP gradually decreased to normal levels. However, obstructive and restrictive respiratory failure still progressed. Computed tomography of the inspiratory and expiratory phases revealed obstructive pulmonary disorder, leading to a diagnosis of bronchiolitis obliterans (BO). The patient underwent plasma exchange and was repeatedly treated with rituximab monotherapy and rituximab-containing chemotherapies, but died 7 months after the diagnosis of BO. Early introduction of rituximab-containing regimens may be necessary to prevent the development of BO accompanying PNP. However, when a diagnosis of PNP-related BO is made, lung transplantation may also be considered for patients in whom rituximab-containing regimens are effective for PNP.