Myeloid Sarcoma Arising in a Rare Anatomical Location: A Case Report.

Myeloid sarcoma (MS) is a rare extramedullary tumor of immature myeloid cells that can occur concurrently with acute myeloid leukemia (AML), precede its onset, or present in isolation. Gastrointestinal involvement is uncommon, and diagnosis is often challenging due to non-specific imaging features and clinical presentation. We report the case of a 75-year-old patient with newly diagnosed AML who was found to have synchronous cecal wall thickening and an adjacent hypodense lesion on abdominal computed tomography (CT). Due to an impending obstruction, surgery was performed, and the patient underwent ileocecectomy with primary anastomosis. Histopathology revealed extensive infiltration of the intestinal wall by immature hematopoietic cells, immunopositive for leukocyte common antigen (LCA), myeloperoxidase (MPO), and c-Kit, consistent with synchronous MS. Postoperatively, the patient was managed with standard AML therapy (chemotherapy with cytarabine plus an anthracycline was initiated). MS is difficult to diagnose radiologically and may mimic other malignancies or inflammatory processes. Definitive diagnosis relies on histopathology and immunohistochemistry. No standardized treatment exists; AML-based chemotherapy remains the mainstay, with hematopoietic stem cell transplantation considered for treatment intensification. Surgical intervention is reserved for complications such as obstruction or perforation. This case underscores the rarity and diagnostic challenge of synchronous MS in AML. Early recognition requires high clinical suspicion, and diagnosis depends on pathology. Further studies are needed to guide optimal management strategies.