Neural cell-adhesion molecule (CD 56)-positive, t(8;21) acute myeloid leukemia (AML, M-2) and granulocytic sarcoma

A 49-year-old man with t(8; 21) acute myeloid leukemia relapsed 8 months after successful induction chemotherapy with a paraspinal granulocytic sarcoma. There was no evidence of leukemia in the bone marrow at relapse. At initial presentation, the blasts co-expressed CD 15, CD 33, CD 34, CD 45, CD 19, and CD 56 (a neural cell-adhesion molecule). Expression of certain cell-adhesion molecules on leukemic blasts may determine a tendency to develop extramedullary relapse. The co-expression of CD 56 may have a role in the predisposition of t(8; 21) AML to develop GS.