[Clinicopathological features of primary central nervous system T-cell lymphomas]

Objective: To investigate the clinicopathological features, diagnosis and differential diagnosis of primary central nervous system T-cell lymphomas (TPCNSL), and to analyze its biological behavior and prognosis. Methods: Three cases of TPCNSL were collected from September 2014 to September 2019 in the First Affiliated Hospital of Nanjing Medical University. They were evaluated by HE, immunohistochemistry (IHC) and molecular genetics, and the relevant literature was reviewed. Results: Among the 6 816 brain tumors, 97 were primary central nervous system lymphomas (PCNSL), including 3 TPCNSL. There were two male and one female patients, aged 60, 67, and 82 years. Clinically, they were presented with varying degrees of limb numbness and unstable gait. Microscopically, the tumor cells were distributed diffusely or around blood vessels. They showed significant atypia and brisk mitotic activity. By IHC, they were positive for LCA, CD3, CD43, TIA-1, and perforin. Two of three cases were positive for CD5 and granzyme B. T-cell receptor gene rearrangement was clonal. EBER in situ hybridization was negative. The patients were followed for 1 to 6 months; one patient received chemotherapy and died of recurrence 3 months after surgery. One patient died of recurrence 5 months after operation alone. One patient remained recurrence and metastasis free more than 4 months post surgery. Conclusions: PCNSL is uncommon, and most are B-cell lymphomas, while T-cell lymphomas are even rarer. As the latter may show atypical clinical manifestations, diverse histologic morphology and poor prognosis, early diagnosis and timely treatment are particularly important for patients to improve survival.