Extramedullary Acute Leukemia—Still an Unforeseen Presentation

Myeloid sarcomas (MS) are rare extramedullary (EM) hematological tumors that generally arise during the natural course of acute myeloid leukemia (AML), occurring concomitantly with the onset of systemic leukemia; it can also occur following onset but rarely before. Common sites of EM involvement include the lymph nodes, skin, soft tissue, bone and peritoneum. Herein, we report the case of a 63-year-old man who presented EM AML upon initial diagnosis involving the bone marrow, lymph nodes and skin (leukemia cutis). A diagnosis was made based on immunohistochemistry (IHC). This case presents a diagnostic dilemma due to its atypical presentation and the sites involved. It also highlights the importance of IHC in the diagnosis of EM AML. The potential role of hypomethylating agents and Venetoclax in cases not eligible for hematopoietic stem cell transplant are also discussed.