T-Cell Lymphoblastic Lymphoma with Peripheral Eosinophilia: A Rare Clinical Presentation

Abstract

T-cell lymphoblastic lymphoma (T-LBL) is a rare and aggressive form of Non-Hodgkin's lymphoma, comprising less than 1% of all adult NHL cases. The co-existence of peripheral eosinophilia with T-LBL is an exceptionally uncommon presentation with significant prognostic implications. We present a case of a 34-year-old male poultry farmer who presented with right-sided pleuritic chest pain, dyspnea on exertion, and dry cough. Clinical and radiological investigations revealed right-sided pleural effusion with anterior mediastinal mass encasing the superior vena cava and ascending thoracic aorta. Pleural fluid analysis demonstrated exudative features with elevated adenosine deaminase (ADA), while absolute eosinophil count was markedly elevated (>1900/µL). Histopathological examination of CT-guided mediastinal biopsy confirmed T-cell lymphoblastic lymphoma with immunophenotyping showing positivity for TdT, CD3, CD4, CD5, CD7, CD8, CD10, and BCL2. The presence of concurrent peripheral eosinophilia associated with T-LBL is documented in only a few cases globally and carries poor prognostic implications with high risk of subsequent myeloid neoplasia. This case highlights the importance of comprehensive evaluation of unexplained hypereosinophilia and the diagnostic challenges in recognizing this rare clinicopathological entity.

Keywords: T-cell lymphoblastic lymphoma, eosinophilia, mediastinal mass, non-Hodgkin's lymphoma, immunophenotyping