Peripheral T cell lymphoma with a high titer of proteinase-3-antineutrophil cytoplasmic antibodies that resembled Wegener's granulomatosis.

Here, we present a 54-year-old man with proptosis and swelling below the left eyelid. Laboratory findings showed high levels of PR3-ANCA and histological examination of the first biopsy revealed acute inflammation. Together with the findings of MRI, a diagnosis of WG was made. However, the disease progressed rapidly and histological examination of the second biopsy revealed infiltration of neoplastic T lymphocytes with aberrant loss of CD7. A final diagnosis of peripheral T cell lymphoma, not otherwise specified (WHO) was made, and complete remission was achieved by chemotherapy. This is a very rare case of T cell lymphoma with a high titer of PR3-ANCA.