Primary malignant fibrous histiocytoma extending into spinal canal through intervertebral foramina

A 60-year-old man was referred to us because of gradual-onset radiculopathy in his left leg for 2 months. Magnetic Resonance Imaging (MRI) of the lumbar spine demonstrated a relatively homogeneous huge mass in the left paravertebral area from L1 to L3 (Fig. 1A, B). Axial MRI scan (Fig. 1C) confirmed the extension of the tumour into the adjacent spinal canal through the neural foramina, forming an extradural mass, which resulted in the compression of both the dural sac and the nerve roots. The patient was operated on by a staged-resection. First, a left retroperitoneal approach was performed for the paraspinal mass. The tumour appeared brown to tan in color and was moderately firm. Nine days after his first operation, the patient underwent a resection of the intraspinal/extradural tumour by a posterior approach. After the left L1-2 hemilaminectomy was performed, the extradural tumour was easily identified, dissected, and completely removed. Microscopically, it was a highly cellular tumour composed of anaplastic cells assuming a gigantic size with bizarre nuclei, which were admixed with inflammatory cells (Fig. 1D). The tumour cells were immunohistochemically characterized by positive staining for vimentin confirming its mesenchymal origin, and CD68 consistent with histiocyte-like qualities (Fig. 1E, F). A diagnosis of inflammatory malignant fibrous histiocytoma (MFH) could be made. Postoperatively, the patient made an uneventful recovery and received radiotherapy as an adjuvant therapy.