case_images: PMC9524614_01
case_images: Image of the neoplastic lesions. (A-C) Neoplastic lesions found on the left side of C7-T2 invading the vertebrae body of T1, T2, and caput costae of the second rib. (D-F) A suspected metastasis was found in the left ilium.
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case_images: T1, T2, and caput costae of the second rib ( Figures 1A-C ). Tumor metastasis in the left ilium was suspected ( Figures 1D-F ). Radiotherapy target planning of thoracic and iliac lesions was presented in  Supplementary Figures 1, 2 .
case_images: Biopsy and staining images of the tumors. (A, B) CT-guided core needle biopsy and the H&E staining images of the thoracic lesion. (C1-C6) Immunohistochemical staining of the thoracic lesion. (D, E) CT-guided core needle biopsy and the H&E staining images of the left ilium lesion. (F1-F6) Immunohistochemical staining of the left ilium lesion. B1, E1: 100x; B2, E2: 400x; (C, F): 200x.
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case_images: Diffuse small spindle cells were found in the hematoxylin and eosin (H&E) staining of both paravertebral ( Figures 2A, B ) and iliac ( Figures 2D, E ) lesions. Immunohistochemical staining of the paravertebral sample was positive for cytokeratin (CK){pan} and vimentin; partially positive for cluster of differentiation 68 (CD68){KP1} and epithelial membrane antigen (EMA); slightly positive for S100 and CD34; and negative for SRY-box transcription factor 10 (Sox10), Langerin, thyroid transcription factor 1 (TTF-1), and prostatic specific acid phosphatase (PSAP) ( Figure 2C ). Immunohistochemical staining of the iliac sample was positive for CK{pan}, vimentin, CD68{KP1}, and epidermal growth factor receptor (EGFR); partially positive for Clusterin; slightly positive for S100, CD35, and CD20; and negative for CD21, Sox10, Langerin, and CXC chemokine ligand 13 (CXCL13) ( Figure 2F ). T3 ( Figures 3A1, 2 ). Radiotherapy target planning of thoracic and iliac lesions was presented in  Supplementary Figures 1, 2 . The pathological examination of the left iliac bone tumor suggested a small amount of bone tissue, fibrous tissue hyperplasia and hemorrhage, myofibroblast reaction, lymphocyte and plasma cell infiltration, a small amount of necrosis, and tissue cell deposition, while no tumor tissue was observed ( Figures 3C1, 2 ).
case_images: Postoperative radiological and pathological images. (A1, 2) Pedicle screw internal fixation was performed at the level of T1-T3. (A3, 4) Postoperative CT scan showed that the left lamina and the facet joint of T1 and T2 were resected. (B1-3) CT examination of the iliac bone showed that the lesion size was slightly larger than that before the 2-month postoperative follow-up. (C1, 2) H&E staining of iliac bone lesion. (D1-3) Thoracic MRI examination showed no significant enlargement of the lesion after 15 months of follow-up. (E1, 2) Pelvic MRI examination showed absence of recurrence of the iliac lesion after 15 months of follow-up. C1: 100x; C2: 400x.
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case_images: T3 ( Figures 3A1, 2 ). The left lamina and facet joint of T1 and T2 were resected ( Figures 3A3, 4 ). The left second costovertebral joint and the second rib head were also resected. Transpedicular curettage was performed to ensure sufficient neural decompression of the tumor, providing a safe target volume for radiation. CT examination of the iliac bone showed that the lesion size was slightly larger than that before the 2-month postoperative follow-up ( Figures 3B1-3 ). The pathological examination of the left iliac bone tumor suggested a small amount of bone tissue, fibrous tissue hyperplasia and hemorrhage, myofibroblast reaction, lymphocyte and plasma cell infiltration, a small amount of necrosis, and tissue cell deposition, while no tumor tissue was observed ( Figures 3C1, 2 ). Thoracic and pelvic magnetic resonance imaging (MRI) examinations showed no significant enlargement or recurrence of the tumors after 15 months of follow-up ( Figures 3D, E ).
case_images: Timeline of the occurrence of major clinical events during the treatment and follow-up.
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case_images: The left lamina and facet joint of T1 and T2 were resected ( Figures 3A3, 4 ). The left second costovertebral joint and the second rib head were also resected. Transpedicular curettage was performed to ensure sufficient neural decompression of the tumor, providing a safe target volume for radiation. The timeline of major clinical events during treatment and follow-up is shown in  Figure 4 .