An exceptionally rare and aggressive malignant bone tumor was positively confirmed via the expressions of a DNA protein transcription factor, according to a recent study by American researchers.
“We herein report an exceptional case of extra-axial dedifferentiated chordoma confirmed by the expression of brachyury, the first case report of this kind,” reported surgical pathologist Dr. Evita Bonita Henderson-Jackson and her research colleagues from Moffitt Cancer Center in Tampa, Florida, United States, in a case report offering literature review and pathologists’ perspective, published by the open-access peer-reviewed journal Advances in Modern Oncology Research (AMOR).
Chordoma, or bone tumor of the skull and spine, is a very uncommon type of cancer with low prognosis (55% for a five-year survival), and accounts for about 3% of all bone tumors. Every year in the United States, according to the Chordoma Foundation, only one new case per million people is diagnosed. In the entire population of 321 million people in the United States, there are scarcely 2,400 chordoma patients.
The tumor primarily occurs within the axial skeleton, along a human body’s spinal axis from the skull to the tailbone. When identified outside of the axial skeleton, these subsets are known as extra-axial chordomas. Chordoma has no known environmental, dietary or lifestyle risk factors, and is believed to emerge from the remnants of embryonic notochord – a rod-shaped, cartilage-like scaffolding structure during the early formation of the spinal column. Notochord cells normally persist after birth, lodged inside the spine and skull, until becoming malignant to form chordoma.
Dedifferentiated chordoma, meanwhile, is a fatal variant of conventional chordoma that is even rarer, occurring in only 2%-8% of all chordomas. It is typically identified following radiation therapy of primary tumors or as recurrences, and with its additional high-grade sarcomatous elements, i.e. malignancies affecting connective tissues, dedifferentiated chordoma is known to be very aggressive and likely to culminate in distant metastases, thus accelerating the patient’s demise to within one year of diagnosis.
It is difficult to identify chordoma – let alone dedifferentiated chordoma – at extra-axial sites, according to the researchers. “There have been only a few reports of primary dedifferentiated chordoma,” they noted. “Owing to its rarity, especially when it is in an unusual extra-axial location, primary dedifferentiated chordoma presents a diagnostic challenge.”