First Confirmed Metastatic Adamantinoma of the Spine: Case Report and Literature Review.

Study Design Case report and literature review. Objective To present the first case of metastatic adamantinoma of the spine with immunohistochemical confirmation and an updated literature review. Summary of Background Data Spinal metastatic disease could be difficult to diagnose because of the multiple differential diagnoses involved. Spinal surgeons must be aware of unusual primary extra-axial tumors that metastasize to the spine because in certain cases the primary surgery must determine the prognosis of this lesion. Methods We present a fully documented case of a middle-aged man with tibial adamantinoma who developed spine metastasis, confirmed by immunohistochemistry. A literature review was done. Results Based on clinical, imaging, and pathology findings, we provide evidence for the first proven metastatic adamantinoma of the spine, adding this condition to the long list of differential diagnoses of secondary spinal disease. Conclusions Adamantinoma is a very rare bone tumor representing ∼1% of primary bone tumors. Spinal metastatic adamantinoma with immunohistochemical confirmation has not been described previously. Due to the lack of specific image findings or serum markers and multiple differential diagnoses, biopsy with immunohistochemical confirmation is mandatory, because "en block resection" might prove to be curative treatment.

An assessment of the reliability of the Enneking and Weinstein-Boriani-Biagini classifications for staging of primary spinal tumors by the Spine Oncology Study Group.

STUDY DESIGN: Reliability analysis based on expert panel case series review and grading per the Enneking and Weinstein-Boriani-Biagini classification systems. OBJECTIVE: To assess the reliability of the Enneking and Weinstein-Boriani-Biagini classification systems. SUMMARY OF BACKGROUND DATA: The Enneking and Weinstein-Boriani-Biagini (WBB) classifications were developed to stage and facilitate treatment planning in patients with primary spine tumors. To date, their interobserver and intraobserver reliability has not been assessed-a fundamental step in facilitating broader clinical and research use. METHODS: Clinical information, imaging studies, and biopsy results were compiled from 15 selected patients with primary spinal tumors. Eighteen spine surgeons independently estimated and scored the cases for Enneking grade, tumor and metastasis categories, Enneking stage, Enneking-recommended surgical margin, WBB zones and layers, and WBB-recommended surgical procedures, with a second assessment performed after random resorting of cases. Interobserver and intraobserver reliability of each category were assessed by percent agreement or proportional overlap. The Fleiss, Cohen, and Mezzich kappa statistics (kappa) were then applied, determined by the type of variable analyzed. RESULTS: The kappa statistics for interobserver reliability were 0.82, 0.22, 0.00, 0.57, 0.47, 0.31, 0.58, and 0.54 for the fields of Enneking grade, tumor and metastasis categories, Enneking stage, Enneking-recommended surgical margin, WBB zones and layers, and WBB-recommended surgical procedures, respectively. The kappa statistics for intraobserver reliability were 0.97, 0.53, 0.47, 0.82, 0.67, 0.63, 0.79, and 0.79 for the same respective fields. According to Landis and Koch, the ranges of kappa values of 0.00 to 0.20, 0.21 to 0.40, 0.41 to 0.60, 0.61 to 0.80, and >0.80 imply slight, fair, moderate, substantial, and near-perfect agreement, respectively. CONCLUSION: Results indicate moderate interobserver reliability and substantial and near-perfect intraobserver reliability for both the Enneking and WBB classification in terms of staging and guidance for treatment, despite a less than moderate interobserver reliability in interpreting the Enneking local tumor extension and WBB sector. Before incorporating the classifications in the clinical practice and research studies, further work is required to investigate the validity of the classifications.