[A case of follicular lymphoma complicated with lethal pemphigus]

Paraneoplastic pemphigus (PNP) is a rare autoimmune bullous disease associated with neoplasm, which is clinically characterized by mucocutaneous lesions resembling pemphigus vulgaris or erythema multiforme. A case presented with PNP refractory to chemotherapy including rituximab, predonisolone and cyclophosphamide (RCHOP regimen). A 36-year-old man, who had been diagnosed as extended follicular lymphoma, presented with a polymorphous skin eruption of the trunk, sclera conjunctivitis, and severe mucosal erosions of the lips and oral cavity. He was diagnosed as pemphigus pathologically by a biopsy of the oral mucosa. However, 3 courses of rituximab and CHOP therapy, which exert a partial response with lymphoma lesions, did not prove effective for oral stomatitis due to pemphigus. He received corticosteroid therapy (prednisolone 40 mg/day) and went into a state of temporally remission regarding pemphigus. However, the mucosal lesions were again exacerbated despite control of the lymphoma status after chemotherapy. Oral stomatitis extended to the upper respiratory system through the larynx and resulted in bronchiolitis obliterance clinically presented likely as severe chronic obstructive pulmonary disease (COPD). Because it is known that PNP refractory to long-term steroid and cytoreductive therapy has a progressive character and poor prognosis, supportive care would be warranted for these patients.