Histopathologic Classification of Spinal Chordoma

Proper histopathologic classification of notochordal tumors is key to prognostication as notochord-derived lesions demonstrate significant variability in malignant potential and expected survival. Benign notochordal cell tumor (BNCT) is a benign tumor showing notochordal differentiation with an excellent outcome; it rarely requires surgical intervention. Conversely, conventional chordoma is malignant, like other spinal sarcomas, and has metastatic potential. Other, less common, histologic subtypes, i.e., dedifferentiated and poorly differentiated chordoma, are similarly malignant and frequently benefit from aggressive surgical resection and management by a multidisciplinary team. Here, the characteristic histopathologic and immunohistochemical features of these various chordoma subtypes are discussed. Also highlighted are prior works focusing on the prognostic significance of specific mutations and the potential role for genetic analysis in the future management of chordoma.