Primary leiomyosarcoma of the spine

RATIONALE Primary leiomyosarcoma of the bone was firstly reported by Evans and Sanerkin in 1965, whereas primary leiomyosarcoma of the vertebra is extremely rare. Because of the rarity of primary vertebral leiomyosarcoma, the diagnosis, treatment, and clinical outcome still remain controversial. Here we report a special case of primary leiomyosarcoma in the thoracic vertebra. PATIENT CONCERNS A 47-year-old female patient was admitted to our institution with the chief complaint of persistent back pain for 4 weeks. She had no symptoms of numbness, weakness, pain, and abnormal sensation in her extremities. DIAGNOSES Neurological examination on admission revealed no obvious abnormality. Magnetic resonance imaging showed a bone destruction of the T11 vertebral body and the right pedicle. Therefore, primary vertebral leiomyosarcoma was suspected. Pathological hematoxylin and eosin staining of the resected tumor revealed a diagnosis of polymorphic undifferentiated sarcoma. Furthermore, to identify the subtype of this sarcoma, the immunohistochemical staining of the tumor was performed with each of the various antibodies and the results are epithelial membrane antigen (-), H-caldesmon (-), desmin (+), smooth muscle actin (+), S-100 (-), myogenin (-), pan-keratin (-), and Ki-67 (positive rate: 20%). Finally, the patient was diagnosed as primary vertebral leiomyosarcoma. INTERVENTIONS the anterior corpectomy and autogenous iliac bone graft with instrumentation combined with the posterior spinal canal decompression and fusion with the pedicle screw system were performed through an anterior-posterior union approach. OUTCOMES Neither clinical symptoms nor signs of tumor recurrence were detected within the follow-up of 6 months. In addition, 11 cases of the primary vertebral leiomyosarcoma reported in the literature were reviewed and summarized. LESSONS Exclusion of metastatic leiomyosarcoma by various imaging modalities and histopathological examinations, especially the immunohistochemical staining with various antibodies against the epithelial and mesenchymal cell markers, are critical for establishing the correct diagnosis of the primary vertebral leiomyosarcoma. Surgical resection, especially the total en bloc spondylectomy, is the main treatment option with a good outcome, albeit with a limited follow-up duration.