Peripheral T-cell lymphoma mimicking granulomatosis with polyangiitis.

Upper respiratory tract involvement is common in patients with granulomatosis with polyangiitis (GPA), but malignancies should be kept in mind in the differential diagnosis. A 68-year-old man was referred to rheumatology to investigate for GPA after nasal excisional biopsy. After careful radiologic and pathologic assessment, he was diagnosed with peripheral T‑cell lymphoma, nasal type. This is a rare case of T‑cell lymphoma in a patient who was referred as GPA.