Spinal granulocytic sarcoma with both extradural and intradural involvement: a case report

Granulocytic sarcoma (GS) is a rare extramedullary accumulation of myeloid blasts. Cases of GS with isolated intradural presentation sparing the underlying bone are extremely rare.

A 75-year-old male patient with a remote history of acute myeloid leukemia (AML) in 30-year remission presented with progressive lumbar radiculopathy. Magnetic Resonance Imaging (MRI) revealed intradural lesions spanning L2-S1, mimicking nerve sheath tumors. The patient underwent emergency laminectomy and resection of a vascular, grayish-green L2 mass adherent to the cauda equina. Immunohistochemistry confirmed it was a GS (MPO+, CD43+, CD68+) with no evidence of bone marrow relapse. Following surgery and consolidation chemotherapy, the patient's neurological status improved (ASIA C to D). However, he developed disseminated CNS relapse four months later and succumbed to disease progression 7 months postoperatively.

Isolated intradural GS constitutes a rare manifestation of extramedullary AML relapse and frequently masquerades radiologically as common benign nerve sheath tumors. While urgent surgical decompression facilitates significant neurological recovery, long-term survival is strictly dictated by the efficacy of systemic disease control. Therefore, adopting a multidisciplinary strategy integrating intraoperative frozen-section analysis, rigorous immunohistochemical profiling, and early adjuvant chemotherapy is paramount for avoiding diagnostic delays and optimizing patient outcomes.