Supplementary Material for: Acute Promyelocytic Leukemia Presenting with Cranial Nerve Involvement and Clivus Mass

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia that has become highly curable with advances in targeted therapy. However, central nervous system (CNS) involvement is exceedingly rare in APL and poses significant therapeutic challenges due to the limited penetrance of standard therapies across the blood-brain barrier (BBB). While APL is traditionally managed without chemotherapy, cases with CNS involvement require a multimodal approach to achieve effective disease control. We present a unique case of a 31-year-old male with de novo APL and CNS involvement at presentation, including a clival mass. The patient was successfully treated with a combination of systemic chemotherapy, intrathecal chemotherapy and craniospinal irradiation, achieving durable remission. This case highlights the rarity of CNS involvement in APL, the importance of a multidisciplinary approach, and the need to address logistical barriers to treatment in achieving optimal outcomes.