Chordoma and malignant fibrous histiocytoma. Evidence for transformation.

Serial biopsy specimens of a histologically proven cervical chordoma in a 57-year-old woman taken at intervals over a 7-year period, demonstrate a progression and complete transformation to a malignant fibrous histiocytoma 5 years following radiation therapy. Intermediate spindle-shaped cells demonstrating keratin positivity were discovered, lending credence to the theory of cellular transformation. Additionally, a fine reticulin network was noted around the chordoma cells. A review of the literature is undertaken chronicling the documented associations of chordoma and sarcoma, followed by a discussion of the various causes proposed to explain this phenomenon.