Primary Central Nervous System ALK-Positive Anaplastic Large Cell Lymphoma: Clinicopathologic and Prognostic Features

Abstract Background Primary CNS anaplastic lymphoma kinase-positive (ALK+) anaplastic large cell lymphoma (ALCL) is extremely rare and only few cases have been reported. Due to its rarity, the clinicopathologic features and the prognosis of primary CNS ALK + ALCL have not been well characterized. Methods We retrospectively analyzed the clinicopathologic and prognostic features of 3 cases of primary CNS ALK + ALCLs among 337 cases of primary CNS lymphomas during the past 14 years in our cancer center with review of an additional 20 cases from the literature. Results Primary CNS ALK + ALCL accounted for 0.9% (3/337) of all primary CNS lymphomas during the study period in our cancer center. The ages of patients ranged from 4 to 43 years, with a median age of 18 years. There was a predominance of males, with the male-to-female ratio of 6.7:1. Most (87%, 20/23) of cases had intracerebral mass(es), and among these cases, 25% (5/20) of cases were accompanied by involvement of spinal cord and (or) leptomeninges; rare cases (3/23,13%) were confined to the spinal cord and (or) leptomeninges. A solitary mass and multiple tumors were present in 56.5% (13/23) and 43.5% (10/23) of cases, respectively. Of the 22 patients with survival data, 31.8% (7/22) of patients died of the disease during the follow-up period (median follow-up, 24 months; range, 0.5–87 months). The 2-year overall survival (OS) of patients with primary CNS ALK + ALCL was 69%. Patients under 18-years old had worse 2-year overall survival, but the difference did not reach statistical significance (p = 0.115). No statistical significance was found between patients with solitary mass and multiple tumors (p = 0.940). Conclusions Primary CNS ALK + ALCL is an extremely rare disease and tends to occur in young adults with a male preponderance. Patients with this disease have relatively favorable outcome than other types of primary CNS lymphomas. Accurate diagnosis, as well as timely and optimal treatment for patients with this disease is important.