Recurrent T-lymphoblastic lymphoma in a pediatric patient with bilateral breast and skin involvement: A rare clinical presentation.

Introduction and importance: T-lymphoblastic lymphoma (T-LBL) is a rare and aggressive subtype of precursor T-cell lymphomas, often presenting with lymph node, bone marrow, and mediastinal involvement. Cutaneous involvement is uncommon but associated with a poor prognosis. Case presentation: We report the case of a 17-year-old female with relapsed T-LBL presenting with bilateral breast masses, confirmed by biopsy and immunohistochemistry. Initial treatment with a BFM ALL chemotherapy protocol resulted in partial response, but disease recurrence with cutaneous and cervical lymph node involvement necessitated further treatment with the ALLIC BFM 2016 Relapse protocol. The disease course was complicated by avascular necrosis requiring hip arthroplasty, and follow-up PET/CT scans revealed further extranodal involvement, including the skin. Discussion: Extranodal involvement in peripheral T-cell lymphomas (PTCL), such as T-LBL, poses significant challenges to clinical management due to its association with aggressive disease and poor prognosis. Standard CHOP regimens often result in short-term remission with high relapse rates. Emerging therapies, including HDAC inhibitors, proteasome inhibitors, and immunotherapies, show promise but require further study to address tumor heterogeneity and optimize efficacy. Conclusion: This case underscores the critical role of early diagnosis and effective multidisciplinary management in relapsed T-LBL with skin involvement. Further research is needed to develop personalized therapeutic strategies to improve outcomes in this rare and aggressive lymphoma subtype.