Intraspinal mesenchymal chondrosarcoma:report of a case

CHEN Hao; CHEN Qiu-yue; WEI Zong-chen; TANG Fang

doi:10.3969/j.issn.1007-8096.2025.01.031

Abstract：Objective To investigate the clinical and pathological features of intraspinal mesenchymal chondrosarcoma (MC). Methods A case of intraspinal MC was reported, and its clinical and pathological features were analyzed along with a review of the literature. Results The patient was a female, 11 years old, who presented with low back pain and bilateral foot pain for one month. MRI and CT scans showed a mass in the L4 spinal canal. Surgical decompression and removal of the mass were performed. Microscopically, the tumor consisted of undifferentiated primitive mesenchymal components and hyaline cartilage, showing a biphasic pattern. The undifferentiated area showed sheets of spindle-shaped cells, which were small, uniform, with inconspicuous nucleoli and rare mitotic figures. The stroma contained arborizing vessels. The cartilage area contained only a few cells or formed cartilage islands, with irregular calcification foci in the center of the islands. The matrix was mainly composed of immature, pink-staining osteoid-like material, with indistinct cartilage lacunae. Immunohistochemical results: The undifferentiated area was positive for SOX9, CD99, NKX3.1, NKX2.2, and Olig-2; the cartilage island area showed positivity for SOX9 and S-100 in chondrocytes. FISH testing revealed breakage and translocation of the NCOA2 gene. Conclusion Intraspinal MC is rare, commonly occurring in adolescents, and primarily presents with neurological compression symptoms such as pain. Diagnosis requires combination of the biphasic differentiation morphology, immunohistochemistry, and molecular testing. Current treatment involves complete tumor resection combined with chemotherapy.