Primary central nervous system ALK-negative anaplastic large cell lymphoma
There are only nine cases reported in the literature to date, most of which have an overall survival time of no more than 8 months. Yuan et al. reported such a rare case that has a good outcome with the longest survival time and performed a literature review 1).
George et al. reported four new cases of primary central nervous system ALCL from the Mayo Clinic and incorporated additional data from five previously published cases. ALK-1 expression was determined in all nine tumors. Patient age was 4-66 years (mean 29 years) with a bimodal distribution: 6 < or = 22 years, 3 > or = 50 years. Six were female. Tumors were mostly supratentorial, five were multifocal, and seven had involvement of dura or leptomeninges. Seven tumors were T cells, two were null cells, and five of nine were ALK-1 immunopositive. Total mortality was six of nine. Three patients, 4-18 years of age (mean 13 years), were alive at 4.8-6.1 years postdiagnosis; these tumors were all ALK-positive. Five patients, 13-66 years of age (mean 43 years), died of tumor 4 days to 11 weeks postdiagnosis; four of five of these tumors were ALK-negative. One 10-year-old child with an ALK-positive tumor died of sepsis, but in remission. The central nervous system ALCL is aggressive. The study suggests that a better outcome may be associated with young age and ALK-1 positivity, prognostic parameters similar to systemic ALCL 2).
A review demonstrated that ALK-negative ALCL exhibits a poor prognosis and is very often fatal. The majority of ALK-negative patients were treated with radiotherapy or supportive care, due to their older age or poor PS. As ALK-negative ALCL tends to occur in older individuals, similar to PCNSL and DLBCL, chemoradiotherapy including HD-MTX should be initiated earlier.
In conclusion, findings indicate that the prognosis of ALCL of the CNS is correlated with ALK positivity and patient age of <40 years. Chemoradiotherapy with MTX is recommended as the standard treatment for ALCL. However, additional multicenter studies including large numbers of cases are required 3).
A 19-year-old male patient was admitted to the hospital complaining of dizziness. CT and MRI imaging showed a heterogeneous enhanced lesion in the left parieto-occipital lobe and the leptomeninges of the occipital lobe and the cerebellum. The lesion was resected and confirmed to be ALK-negative ALCL by pathological examination. Then, the patient received 10 cycles of chemotherapy with high-dose methotrexate (HD-MTX) and whole brain radiotherapy. The patient recovered well and was regularly followed up. He was free of symptoms without recurrence on imaging examination 3 years later. ALCL is a rare type of PCNSL. HD-MTX combined with radiation is an effective therapeutic approach. However, further prospective studies with a large number of patients are needed to identify the biological characteristics of this rare type of PCNSL 4).