Possible role of a malfunctioning immune system in discordant lymphoma with peripheral T‑cell lymphoma secondary to classical Hodgkin lymphoma: A case report.

The present case report investigated the clinicopathological features and potential mechanisms underlying the transformation to peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), following treatment for classical Hodgkin lymphoma (CHL) in a 73-year-old man. The patient was admitted to hospital in 2012 and underwent a left cervical lymph node biopsy, which confirmed CHL of the nodular sclerosing type, with evident bone marrow involvement. The patient received four cycles of doxorubicin, bleomycin, vinblastine and dacarbazine chemotherapy, after which they achieved complete remission. However, after 3 years, the patient presented with enlarged left inguinal lymph nodes and a biopsy revealed PTCL-NOS. Molecular studies indicated a T-cell receptor-γ gene rearrangement. A literature review, together with the current case, identified 11 patients with CHL that transformed into PTCL-NOS. Among these, nine patients (81.82%) were middle-aged or elderly (>45 years old), and eight (72.73%) experienced transformation within 3 years post-treatment of CHL. Among these eight patients, seven (87.50%) predominantly exhibited the nodular sclerosis subtype, with a median recurrence time of 26 months. Five (45.45%) patients died of the disease. The rare transformation of CHL to PTCL-NOS, primarily among men, underscores its clinical significance. Notably, nodular sclerosing-type CHL appears to be particularly prone to transformation into PTCL-NOS. The poor prognosis in such cases may be attributed to the complex tumor microenvironment of CHL.