IntroductionWith improved survival in acute myeloid leukemia (AML), second primary malignancies (SPMs) have emerged as significant long-term complications. Unlike relapse, SPMs are distinct malignancies arising from a different clonal origin.The occurrence of T-cell lymphoblastic lymphoma (T-LBL) following sustained AML remission is exceptionally rare, posing diagnostic and therapeutic challenges.
ObjectivesTo describe a rare case of T-LBL occurring nine years after AML remission, emphasizing clinical presentation, early recognition, and therapeutic considerations.
MethodsA 58-year-old male in complete AML remission for nine years presented with night sweats and weight loss. Chest X-ray incidentally revealed a mediastinal mass. Contrast-enhanced CT and a subsequent PET/CT were performed, demonstrating intense FDG uptake (SUV max 16.4). A tissue biopsy was obtained from the mass, and bone marrow evaluation was performed to exclude AML relapse. The patient received an acute lymphoblastic leukemia (ALL)-type regimen (hyper-CVAD alternating with high-dose methotrexate and cytarabine) followed by consolidating allogeneic stem cell transplantation.
ResultsBiopsy confirmed T-LBL, with tumor cells positive for CD3, TdT, CD5, CD7, CD99, and Ki-67 >95%. Bone marrow evaluation excluded AML relapse. After two chemotherapy cycles, the patient achieved significant radiologic and metabolic remission, with PET showing SUV max reduction from 16.4 to 2.6 (Deauville score 3). Post-transplant, he remains in remission on immunosuppression and maintenance intrathecal chemotherapy.
ConclusionThis case highlights the need for lifelong vigilance regarding SPMs in long-term AML survivors, as late secondary hematologic malignancies can occur. Aggressive, ALL-based chemotherapy followed by allogeneic stem cell transplantation may be an effective strategy for this rare secondary malignancy. Collaborative studies are needed to better define optimal treatment protocols for adult T-LBL.
