Objective: To investigate the clinicopathological and immunohistochemical features of lymphoblastic lymphoma (LBL).
Methods: A retrospective clinicopathological study of 96 cases LBL was carried out. Immunohistochemical staining was used for the characterization and immunophenotyping.
Results: The patients age ranged from 4 to 72 years, with a median of 16 years, 69 patients were male and 27 female. Seventy-three cases had superficial or multi-lymphoadenopathy and 31 of them had mediastinal masses. Bone marrow was involved in 15 cases. Seventy-three cases were in clinical stages III and IV. The median survival of the followed-up patients was 5.5 (2 approximately 120) months. TdT and CD99 positive reactions were 75.0% and 92.7%, respectively. Of the 96 cases, 78 displayed T-cell marker positivity and 18 B-cell markers. 82.1% of the patients younger than 30 years of age had significantly higher incidences of T-LBL (64 patients), and 93.6% of the patients with mediastinal masses expressed T-cell markers. The poor prognostic factors were T-cell tumors, clinical stages III and IV, Ki-67 PI < 80% and no chemotherapy (P < 0.01).
Conclusion: In children and young males, mediastinal masses with superficial or multi-lymphoadenopathy favors the diagnosis of LBL, but negative TdT reaction can not exclude this diagnosis. T-LBL is more common than B-LBL. Clinical stages, immunophenotypes and the level of Ki-67 expression were closely related with prognosis of LBL.