Unveiling T-Cell Prolymphocytic Leukaemia: A Comprehensive Case Study on Diagnostic Markers and Challenges

Background: T-PLL is a rare T cell Chronic Lymphoproliferative disorder (T-CLPD), representing about 2% of mature lymphocytic leukaemia in adults over age of 30 years, with a median diagnosis age of 65 years. It commonly presents with symptoms like hepatosplenomegaly, generalized lymphadenopathy and occasionally skin infiltration or serous effusion.

Methods: The subject, a 40-year-old male, presented with symptoms such as high white blood cell counts, anemia, lymphadenopathy, and hepatosplenomegaly. A peripheral blood sample was subjected to flow cytometric immunophenotyping to assess the expression of T-cell markers, including CD2, CD3, CD4, CD5, CD7, CD8 and CD38. The analysis focused on characteristic marker profiles consistent with T-PLL.

Results: Flow cytometry revealed a mature T-cell immunophenotype with CD2+, CD3 (dim to negative), CD4+, CD5+, CD7+, and CD38 (strongly positive). The CD4+/CD8- profile was noted, with rare co-expression of CD4 and CD8 observed in this case. These findings supported a diagnosis of T-PLL, aligning with known immunophenotypic features, including dim or absent surface CD3 expression which is commonly associated with T-PLL.

Conclusion: Flow cytometry is essential in the accurate diagnosis of T-PLL, providing the detailed immunophenotypic insights that enable differentiation from other lymphoproliferative disorders. This case underscores the importance of understanding T-PLL's characteristic markers in guiding diagnosis and management.