Intra-articular extra-axial chordoma of the wrist: a case report with review of the current literature.

Chordomas are rare bone malignancies that are thought to arise from remnants of the notochord and usually are located in the axial skeleton. Immunophenotypical matching neoplasms primarily found in appendicular locations, referred to as extra-axial chordoma, are rarely encountered by radiologists, surgeons, and pathologists. Only a few of these cases have been described in the literature with only one intra-articular case with involvement of the knee joint. We present the first case of an intra-articular extra-axial chordoma of the wrist. Diagnostic imaging patterns were initially ambiguous and histopathological reprocessing was crucial in order to determine the diagnosis of an intra-articular neoplasm with co-expression of cytokeratins, S-100 protein, and brachyury.