Primary vertebral leiomyosarcoma masquerading as a nerve sheath tumour

Abstract

A 47-year-old woman presented with symptoms of low back pain and weakness in bilateral lower limbs. MRI of the spine revealed a mass arising from T11 vertebra involving neural foramina at bilateral T11-12 and right T10-11 levels with extension to the right paravertebral region. Suspecting a nerve sheath tumour, she underwent posterior spinal decompression, stabilisation and debulking, following which her neurological symptoms resolved. Histopathological and immunohistochemical evaluation revealed a leiomyosarcoma. A month later she developed sudden paraparesis and MRI revealed an increase in size of the tumour with cord compression and displacement. She underwent a repeat spinal decompression and debulking procedure after which she received adjuvant radiotherapy via volumetric modulated arc therapy, to a total dose of 45 Gy in 25 fractions over 5 weeks. MRI performed 2 months later revealed complete response and she is disease free for the past 5 months.

Figure 1

Preoperative MRIs. (A and B) Images in T2 sagittal and coronal planes reveal marrow infiltration of T11 vertebra (black arrow). There is an extraosseous extension of the soft tissue mass into epidural (red arrow) and paravertebral space with extension in paraspinal region through right T10–11 and T11–12 neural foramina (blue arrows). Also note involvement of left T11–12 neural foramina (orange arrow). (C and D) Postcontrast images in sagittal and coronal planes reveal moderate-to-intense heterogeneous enhancement of the T11 vertebra (black star) and extraosseous soft tissue component. Epidural component of the soft tissue is compressing the spinal cord (green arrow).

Figure 2

(A and B) Preoperative CT images from positron emission tomography-CT scan in axial and coronal planes reveals a mixed attenuation soft tissue mass lesion in spinal canal extending into bilateral neural foramina and paraspinal region with widening of neural foramina. (C and D) Postoperative treatment planning CT images in axial and coronal planes shows the clinical target volume (in green contour) and planning target volume (in red contour).

Figure 3

(A and B) Dose colour wash in axial and coronal planes with lower limit set to 95% of prescription dose. Only the superomedial region of the right kidney was enveloped at this dose level (black arrows). (C) Cumulative dose–volume histograms (DVH) of selected structures. 99.9% of the planning target volume (red line) received at least 95% of the prescribed dose. DVH of combined kidney volume (dotted yellow line), the right kidney (cyan arrow) and left kidney (white arrow). The mean dose (D_mean; not shown here) of the combined kidney volume was 12.01 Gy, whereas the right and left kidney received a D_mean of 12.6 and 11.3 Gy, respectively.