Adult T-cell leukemia (ATL) cells which express neural cell adhesion molecule (NCAM) and infiltrate into the central nervous system.

We encountered a patient with adult T-cell leukemia/lymphoma (ATL) which expressed neural cell adhesion molecule (NCAM). The tumor cells markedly infiltrated the central nervous system (CNS) during the course of the ATL. The patient died 20 months after disease onset, which was considered to be early in the course. During the invasion of the CNS, the surface phenotype of the peripheral blood ATL cells by flow cytometric analysis was CD2+, CD3+, CD4+, CD7-, CD8-, CD16-, NCAM (CD56)+, HLA-DR-. We speculate that the infiltration of ATL cells into the CNS was closely related to the expression of the NCAM in this patient.