Myeloid Sarcoma as Presenting Feature of Late Isolated Central Nervous System Relapse Post-Bone Marrow Transplant.

Isolated central nervous system (CNS) relapse in patients of acute myeloid leukemia (AML) post-transplant is a rare clinical scenario. We present a case of intermediate-risk AML diagnosed five years ago who underwent matched sibling allogeneic hematopoietic stem cell transplantation (HSCT) following standard induction chemotherapy. He presented with symptoms suggestive of cerebellar dysfunction, and imaging studies revealed a large homogeneously enhancing lesion along the tentorium cerebelli. Flow cytometric immunophenotyping (FCM IPT) and cytomorphology of cerebrospinal fluid (CSF) clinched the diagnosis of isolated CNS relapse as bone marrow was uninvolved. This case highlights the necessity for surveillance of CNS symptoms following transplantation, even in AML. Clinical Trial Registration Not applicable.