Clinical features and pathobiology of chordoma

Chordoma is the most common primary malignant bone tumor found in the spine and sacrum. While these tumors are relatively slow growing, they do have the potential to recur and metastasize. Chordoma was described histologically long before it was realized that they were probably derived from notochordal precursor cells. Early reports dating back to Virchow in 1857 describe a vacuolated cell type seen in these tumors. These cells were described as physaliferous, from Greek for having bubbles. It was thought at that early time that they were a cartilaginous tumor, which may have been a result of evaluation of a chondroid variant tumor. By 1923, Burrow and Stewart recognized that chordomas were a lowly malignant tumor of slow growth, locally invasive and destructive, and only rarely giving rise to metastases. By then, the location at either end of the spine correlated well with contemporary descriptions of the location of vestigial notochordal remnants by Muller. These observations led to the hypothesis that chordomas were not tumors of the intervertebral disc but rather malignant transformation of these notochordal remnants. In 1858, Muller coined the current name by proposing the following hypothesis: A direct relation of these growths to the chorda dorsalis cannot be overlooked and I consider them to be excessively growing remnants of the chorda. Whosoever likes the name may designate these masses as chordoid tumors, or chordomas. Since these early descriptions, this concept has been supported by significant indirect evidence, although there is a paucity of direct proof.