Lessons in balancing function with oncological control in a destructive lumbosacral tumor of uncertain pathology: illustrative case.

BACKGROUND

Ambiguous destructive lumbosacral tumors with intractable pain and neurological compromise present a dilemma between timely decompression and oncological adequacy. The authors present a rare case of primary unclassified sarcoma of the sacrum to illustrate the implications of diagnostic uncertainty in surgical decision-making.

OBSERVATIONS: A 59-year-old woman presented with excruciating low back pain and bilateral sciatica from a destructive lumbosacral mass spanning L5-S4 with circumferential cauda equina compression. CT-guided biopsy demonstrated an atypical epithelioid and spindle cell neoplasm, not otherwise classified. Given rapid neurological decline and refractory pain, she underwent preoperative embolization and urgent posterior decompression with multilevel laminectomies (L4-S4), transpedicular corpectomies (S1-3), and lumbopelvic fixation, followed by paraspinous flap closure. Frozen-section analysis favored a tenosynovial giant cell tumor (TGCT) to support a nerve root-sparing resection. Postoperative MRI showed small residual enhancement at S1-2. Final pathological analysis revealed an intermediate-grade unclassified sarcoma, and she subsequently underwent adjuvant radiation therapy. Systemic staging is ongoing. At the 6-month follow-up, she reported durable analgesia and function.

LESSONS: Destructive lumbosacral tumors should be approached with an oncological mindset even when histology is uncertain. In urgent cases, timely decompression and functional preservation may outweigh radical resection, underscoring the value of adaptable, multidisciplinary management. https://thejns.org/doi/10.3171/CASE2646.