[Chordoma - a review and report of two cases (author's transl)].

Chordomas can be categorized into those of clival, cervical and sacrococcygeal origin. The clival chordomas are primarily discussed in this report. In defining pathological anatomy or histology, a differentiation of benign from malignant chordomas by histological means alone is impossible. A preoperative diagnosis is only possible if tumor grows into the nasopharynx and allows a tissue biopsy to be taken. These tumors are clinically malignant though strict anatomic criteria for malignancy such as nuclear polymorphia or atypia, mitoses and metastases are rarely observed. The therapeutic results of operation and radiation are compared. Each alone fails because of the high recurrence rate of the tumor so that their combination is preferred. Although the prognosis of this disease is poor, one of our patients who was treated with radiation and surgery had a survival time of 14 years.