Decitabine treatment of extramedullary relapse in one patient with T-ALL transformed from myelodysplastic syndrome after allo-PBSCT

Abstract

Objective: To report the critical role of decitabine in treatment of a patient with T cell acute lymphoblastic leukemia (T-ALL) transformed from myelodysplastic syndrome (MDS) post-transplantation.

Methods: This patient initially displayed MDS-refractory cytopenia with multilineage dysplasia (RCMD) with a chimeric chromosome of trisomy 8 and normal karyotype. Two years later, he had progressed to T-ALL, his karyotype had completely transformed to trisomy 8. Six months after a matched-related allogeneic peripheral blood stem cell transplantation (allo-PBSCT), he presented with a tumor measuring 5.5 × 3.9 × 7.1 cm in front of the mediastinum that was metabolically active (SUV_max 6.6), assessed using position emission tomography–CT (PET–CT). Tumor immunostaining was positive for CD3, TdT, CD99, CD4, CD8 and Ki67, suggestive of T cell lymphoblastic lymphoma. One month after immunosuppression had been discontinued, the tumor size decreased to 4.0 × 3.3 × 5.5 cm with a reduction in metabolic activity to 3.0 (SUV_max). Subsequently, he was treated with cyclosporine A and prednisone against chronic graft versus host disease. He was then treated with decitabine alone (20 mg/m²/d, 5 days/month) for 4 months without serious side effects.

Results: Thus far, his bone marrow has remained in complete remission. PET–CT scan revealed a decrease in tumor size to 2.6 × 1.9 × 3.3 cm and a reduction in metabolic activity to 1.5 (SUV_max) without the detection of current disease during therapy.

Conclusions: Decitabine can be used in extramedullary relapse of T-ALL transformed from MDS following allo-PBSCT.

Keywords::

• allo-peripheral blood stem cell transplantation
• decitabine
• extramedullary relapse
• myelodysplastic syndrome
• T cell acute lymphoblastic leukemia