[CD56-positive peripheral T-cell lymphoma primarily presenting with tonsillar swelling].

A 51-year-old woman was admitted to our hospital with tonsillar swelling. After tonsillectomy was performed, she was diagnosed as having CD56-positive T-cell lymphoma, mainly composed of small and medium-sized atypical cells. An immunohistochemical study showed that the malignant lymphocytes were positive for CD3, CD8, CD56, TIA-1 and granzyme B, while negative for CD20, CD5 and CD10. Flowcytometry demonstrated the lymphocytes were positive for CD56. Southern blot analysis revealed a rearrangement of the T-cell receptor gamma chain. The disease stage by Ann Arbor staging classification was II B. We provided MCEC therapy followed by autologous peripheral blood stem cell transplantation, and complete remission (CR) was achieved. Two months after CR, however, the patient relapsed with peritonitis due to perforation of an ileal tumor, and died of sepsis. It is rare for CD56-positive T-cell lymphoma to occur primarily in the tonsils. Because small bowel ulcers were revealed during the course of induction chemotherapy, we report a valuable case in which suspected CD56-positive enteropathy-type T-cell lymphoma (ETL) occurred primarily in the tonsils.