Primary intracranial manifestation of CD7/CD56-positive acute myelogenous leukemia

Background: CD56 which is considered as a marker of natural killer cells is also expressed in some cases of acute myelogenous leukemia (AML) and is in volved in cell adhesion mediating extramedullary leukemic infiltration. CD7 /CD56 coexpression has been suggested to be a distinct biological and clini cal entity of AML. Patient: This is a report of a 53-year-old woman who dev eloped CD7/CD56-positive AML with primary manifestation as intracranial tum or. The patient reported of neurological impairment (impairment of visus an d occurrence of double pictures). Cranial computed tomography showed an int racranial tumor, and histological examination exhibited myeloid blast cells . Peripheral leukocyte count at admission was within the normal range (5,32 Gpt/l), and percentage frequency of blasts in the blood smears was 54%. Cy tological bone marrow examination showed diffuse infiltration by the same m yeloid blast cells. The immunophenotype was CD7/CD13/CD33/CD38/CD56/HLA-DR- positive. The blast cells were myeloperoxidase-positive but lactoferrin-neg ative. Thus, diagnosis of acute myeloid leukemia (M2 FAB) was established. Treatment consists of chemotherapy (Ara-C and anthracycline) and local radi ation of the intracranial tumor. After treatment patient achieved a complet e remission. Conclusion:With regard to the literature CD7/CD56-positive AML have a high incidence of central nervous system involvement which should b e kept in mind and may be associated to CD56 expression.