TY - JOUR
T1 - Phenotypic switch in mycosis fungoides
T2 - A tertiary cancer center experience
AU - Ronen, Shira
AU - McAfee, John L.
AU - Curry, Jonathan L.
AU - Nagarajan, Priyadharsini
AU - Aung, Phyu P.
AU - Ivan, Doina
AU - Prieto, Victor G.
AU - Tetzlaff, Michael T.
AU - Torres-Cabala, Carlos
N1 - Publisher Copyright:
© 2023 Elsevier Inc.
PY - 2023/12
Y1 - 2023/12
N2 - Background: Changes in immunophenotype in mycosis fungoides (MF) are rarely reported, making this phenomenon a diagnostic challenge with unclear significance for the disease's biological behavior. This study examines a large series of MF patients who exhibited a phenotype switch (PS) and analyzes their clinical and histopathologic characteristics. Design: Institutional files were searched for MF cases exhibiting PS between 2010 and 2020. Clinical, follow-up, and histopathological data were collected. Results: Forty-two biopsies from 32 patients (13 women and 19 men, median age 67.5) showed PS. Eight patients (25 %) experienced multiple PS during their disease course. The median time for PS was 22 months from the initial diagnosis. In 5 cases tested, identical TCR clone peaks were detected in the immunophenotypically distinct lesions. Median follow-up was 14.5 months. Among deceased patients, median time from MF diagnosis to PS was 20.6 months, while among the patients who were still alive, median time was 44.1 months. Conclusion: MF biopsies can show PS during the course of the disease and may indicate a change in clinical behavior. 28.1 % of patients displayed more than one PS, further indicating high plasticity of MF cells. No obvious association was found between PS and therapy initiation or response. Features that appeared to portend a worse clinical course were earlier PS in the course of the disease and PS from CD4-/CD8-to CD8+, and CD8+ to CD4-/CD8-. Awareness of this phenomenon is crucial to avoid misdiagnosing phenotypically distinct lymphomas as second primaries and to alert clinicians about potential changes in the disease's clinical course.
AB - Background: Changes in immunophenotype in mycosis fungoides (MF) are rarely reported, making this phenomenon a diagnostic challenge with unclear significance for the disease's biological behavior. This study examines a large series of MF patients who exhibited a phenotype switch (PS) and analyzes their clinical and histopathologic characteristics. Design: Institutional files were searched for MF cases exhibiting PS between 2010 and 2020. Clinical, follow-up, and histopathological data were collected. Results: Forty-two biopsies from 32 patients (13 women and 19 men, median age 67.5) showed PS. Eight patients (25 %) experienced multiple PS during their disease course. The median time for PS was 22 months from the initial diagnosis. In 5 cases tested, identical TCR clone peaks were detected in the immunophenotypically distinct lesions. Median follow-up was 14.5 months. Among deceased patients, median time from MF diagnosis to PS was 20.6 months, while among the patients who were still alive, median time was 44.1 months. Conclusion: MF biopsies can show PS during the course of the disease and may indicate a change in clinical behavior. 28.1 % of patients displayed more than one PS, further indicating high plasticity of MF cells. No obvious association was found between PS and therapy initiation or response. Features that appeared to portend a worse clinical course were earlier PS in the course of the disease and PS from CD4-/CD8-to CD8+, and CD8+ to CD4-/CD8-. Awareness of this phenomenon is crucial to avoid misdiagnosing phenotypically distinct lymphomas as second primaries and to alert clinicians about potential changes in the disease's clinical course.
KW - Cutaneous T-cell lymphomas
KW - Mycosis fungoides
KW - Phenotypic switch
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U2 - 10.1016/j.humpath.2023.10.005
DO - 10.1016/j.humpath.2023.10.005
M3 - Article
C2 - 37977511
AN - SCOPUS:85177878998
SN - 0046-8177
VL - 142
SP - 27
EP - 33
JO - Human Pathology
JF - Human Pathology
ER -