Seeing Beyond the Marrow: Periorbital and Multi-site Myeloid Sarcoma as Extramedullary Manifestations of Acute Myeloid Leukemia

Abstract

Myeloid sarcoma is an uncommon extramedullary manifestation of acute myeloid leukaemia (AML), and orbital involvement in adults is particularly rare. Delayed recognition may occur because periorbital swelling, proptosis, facial swelling and soft-tissue masses can resemble inflammatory or infectious disorders. This case report describes two young adults with AML who presented with prominent periorbital disease and were subsequently diagnosed with myeloid sarcoma by tissue biopsy. The first patient had unilateral periorbital and maxillary swelling with cytopenias and circulating blasts. Bone marrow evaluation confirmed AML, and biopsy of the facial soft-tissue mass confirmed myeloid sarcoma. The second patient presented with fever, progressive periorbital swelling, conjunctival chemosis, proptosis, visual impairment and a breast mass; bone marrow examination confirmed AML with an FLT3 internal tandem duplication mutation, and biopsies confirmed myeloid sarcoma at extramedullary sites. Both patients required transfusion support and received induction chemotherapy followed by high-dose cytarabine consolidation. Given the high-risk context of extramedullary disease, both proceeded to allogeneic haematopoietic stem cell transplantation, with post-transplant FLT3 inhibitor maintenance used in the FLT3-mutated case. These cases emphasise the need to consider myeloid sarcoma in patients with atypical orbital or periorbital masses, particularly when cytopenias or circulating blasts are present. Early tissue diagnosis and AML-directed systemic therapy may support favourable remission outcomes.