Involvement of the appendix in a relapsed case of primary nasal NK/T-cell lymphoma.

We report here a 20-year-old man presenting with primary nasal NK/T-cell lymphoma which showed an aggressive clinical course spreading to the spleen and skin despite various treatments. Eight months after high dose chemotherapy followed by autologous peripheral blood stem cell transplantation, acute appendicitis with perforation occurred and the patient underwent appendectomy. The histopathological diagnosis was NK/T-cell lymphoma of the appendix. Lymphoma of the appendix is extremely rare and the majority of appendiceal lymphomas are of B-cell origin. This is the first report of involvement of appendix by nasal NK/T-cell lymphoma.