Two Cases of T-Cell Large Granular Lymphocytic Leukemia Presenting With Pneumonia and Atypical Lymphocytosis. (21st September 2018)

• Record Type: Journal Article
• Authors: Lu, Ying; Risech, Martina; Bhat, Rekha; Steve Hou, J
• Is Part Of: American journal of clinical pathology. Volume 150(2018)Supplement 1
• Page Start: S93
• Page End: S94
• Publication Date: 2018-09-21
• Subjects: Diagnosis, Laboratory -- Periodicals; Pathology -- Periodicals; 616.07
• DOI: 10.1093/ajcp/aqy097.225
• Languages: English
• ISSNs: 0002-9173

Abstract

Abstract: Objectives: T-cell large granular lymphocytic leukemia (T-LGL) is a chronic lymphoproliferative disorder of cytotoxic T or natural killer cells. It can occur in association with multiple autoimmune conditions. In most cases, it follows an indolent clinical course. Methods: We present two cases of T-LGL that presented with pneumonia, anemia, and lymphocytosis. Patient A is a 27-year-old male with a history of cystic fibrosis and pancreatic insufficiency, presenting with pulmonary exacerbation. Patient B is a 76-year-old male with a history of hypertension, type 2 diabetes, hereditary ataxia, depression, and dementia, presenting with cough and hemoptysis. Results: Peripheral blood smear examination revealed abundant large granular lymphocytes with moderate to abundant cytoplasm and fine or coarse azurophilic granules, normocytic anemia without neutropenia, and thrombocytopenia. Flow cytometry demonstrated the immunophenotype of the atypical lymphocytes to be CD2+/CD3+/CD4–/CD5+/CD7+dim/CD8+/CD56– for patient A and CD2+/CD3+/CD4–/CD5–/CD7+/CD8+/CD56– for patient B. Both cases showed monoclonal TCR gamma gene rearrangement. Conclusion: The hallmark of T-LGL is the expansion of a clonal population of cytotoxic T lymphocytes in the peripheral blood. Both cases are first identified on peripheral blood smear. These two cases also highlight the importance of peripheral blood smear examination in identifying potential atypical lymphocytosis and prompting further appropriate investigation.