ALK and anaplastic large cell lymphoma: The lesions are mainly detected in the parietal lobe, frontal lobe, temporal lobe, and occipital lobe and can invade the pia mater.[4,5] ALCL was first reported as ALK-1 positive pleomorphic or histiocytic-like lymphoma by Stein et al in 1985.[6] According to the World Health Organization (WHO) classification criteria for the central nervous system lymphoma, ALCL is a specific subtype of T-cell lymphoma, accounting for 10% to 15% of children's non-Hodgkin lymphoma.[7] The incidence of primary central nervous system (PCNS) ALCL was low because the number of males was more than that of females.