CD56-positive Angioimmunoblastic T-cell Lymphoma Complicated by Chylothorax

A 77-year-old woman presented with systemic lymphadenopathy and bilateral pleural effusion. Angioimmunoblastic T-cell lymphoma (AITL) was diagnosed based on the results of a lymph node biopsy. AITL cells expressed the aberrant antigen of CD56. The bilateral pleural effusion was attributed to chylothorax, not the infiltration of lymphoma cells into the pleura, as determined by the pleural fluid analysis. We therefore diagnosed her with CD56-positive AITL complicated by chylothorax. She achieved complete remission by multidrug chemotherapy. AITL is commonly complicated by pleural effusion, but rarely by chylothorax. This is the first case of CD56-positive AITL complicated by chylothorax.