Comparison of clinicopathological characteristics between T‐cell prolymphocytic leukemia and peripheral T‐cell lymphoma, not otherwise specified

<jats:title>Abstract</jats:title><jats:sec><jats:title>Objectives</jats:title><jats:p>T‐cell prolymphocytic leukemia (T‐<jats:styled-content style="fixed-case">PLL</jats:styled-content>) is a very rare, aggressive T‐cell neoplasm. Peripheral T‐cell lymphoma, not otherwise specified (<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>) is also a highly aggressive lymphoma. These two diseases can often be confused with each other; therefore, we aimed to determine the clinical and pathological differences between T‐<jats:styled-content style="fixed-case">PLL</jats:styled-content>and<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We analyzed 15 T‐<jats:styled-content style="fixed-case">PLL</jats:styled-content>and 91<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>patients and also compared clinical features between T‐<jats:styled-content style="fixed-case">PLL</jats:styled-content>and<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>with leukemic presentation. Peripheral blood images and biopsy specimens were analyzed, and treatment responses were determined via imaging modalities. The clinicopathological characteristics were statistically compared.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>T‐PLL cells were smaller in size than those of<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>with leukemic presentation (<jats:italic>P</jats:italic>=.0068); moreover,<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>cells with leukemic presentation were smaller than those of<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>without leukemic presentation (<jats:italic>P</jats:italic>=.0017). Immunophenotypic patterns in T‐<jats:styled-content style="fixed-case">PLL</jats:styled-content>and<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>were similar. Five‐year overall survival rates of T‐<jats:styled-content style="fixed-case">PLL</jats:styled-content>and all<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>patients were 57.5% and 36.8%, respectively. No significant differences were found in clinical manifestations or prognoses; T‐<jats:styled-content style="fixed-case">PLL</jats:styled-content>and<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>with leukemic presentation had essentially equivalent characteristics.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>T‐PLL and<jats:styled-content style="fixed-case">PTCL</jats:styled-content>‐<jats:styled-content style="fixed-case">NOS</jats:styled-content>may share common biological and clinical characteristics in Japanese patients.</jats:p></jats:sec>