Context: Granulocytic sarcoma (GS) is an extramedullary form of proliferating myeloblasts. It is frequently reported in patients with acute myeloid leukemia (AML) but rarely in patients with chronic myeloid leukemia (CML). Spinal cord compression caused by CML-associated GS is exceedingly rare, with only few cases reported in the literature. To our knowledge, this is the first reported case in which GS caused such extensive compression.Findings: A 37-year-old man with CML suffered from back pain for 2 months. Notably, he had already achieved molecular remission (MR) after receiving imatinib mesylate for CML; bone marrow aspiration results were consistent with CML in chronic phase. Image examination revealed that developed GS occupied nearly the entire thoracic spinal canal, thereby causing extensive spinal cord compression. The tumor completely diminished after his treatment regimen was upgraded. He showed no signs of recurrence after 1-year follow-up.Conclusion: Extramedullary infiltration of CML should be taken into consideration when a mass lesion develops and compresses the spinal cord in a CML patient who has been receiving routine and standard treatment modalities; thus, a sudden and unexpected progression mandates a refinement and upgrade of treatment modality.
Keywords: Chronic myeloid leukemia; Dasatinib; Granulocytic sarcoma; Imatinib resistance; Spinal cord compression.