CD56 is recognized as an unfavorable prognostic marker in cases of acute myeloid leukemia with t(8;21), acute promyelocytic leukemia, and anaplastic large cell lymphoma.
Tumor cells were CD3(-)/CD56(+); had germline TCR genes; and strongly expressed CD30, epithelial membrane antigen, and anaplastic lymphoma kinase (ALK) consistent with a null cell anaplastic large cell lymphoma (ALCL).
We also studied the expression of these molecules in 92 other cases of T-cell and natural killer (NK) cell neoplasms; 18 anaplastic large cell lymphomas (ALCLs); 63 CD4+ PTCLs; 10 CD56+ nasal lymphomas; and 1 NK-cell leukemia.