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.