Résumé
It is occasionally difficult to distinguish Wegener's granulomatosis (WG) from other diseases including malignancy, tuberculosis, and various types of vasculitis because of the overlapping symptoms and signs. We report on a patient with NK/T cell lymphoma who was treated with a limited form of WG. At his first visit, he presented with left foot drop and recurrent nasal swelling. Necrosis and massive infiltration of inflammatory cells were identified on a nasal tissue biopsy. Sural nerve biopsy findings also showed infiltration of inflammatory cells in both the endoneurium and perivascular area; thus, a diagnosis of a limited form of WG was made. After combination therapy with a glucocorticoid and oral cyclophosphamide was initiated, his condition completely recovered without recurrence for the next 2 years. However, he visited the hospital again for recurrence of nasal swelling. Repeated biopsy of nasal tissues, combined with an immunophenotypic analysis revealed NK/T cell lymphoma. The possibility of NK/T lymphoma should be considered when evaluating a limited type of WG, which shows atypical findings on biopsy as well as recurrent deterioration, as a suboptimal dose of immunosuppressive therapy may mask its expression and lead to a poor prognosis.