Intradural spinal seeding of a clival chordoma

Background. Following recent progress in radiological and surgical techniques for treating skull base tumours, more attention should be paid to the relatively rare phenomenon of intradural spinal seeding in cases of clival chordoma. Case presentation. A 53-year-old man harboured intradural spinal seeding from a clival chordoma 11 years after his initial surgical treatment. He had undergone skull base surgery five times with extra- and intradural approaches, and adjuvant radiotherapy. His complaints of lumbago, paraparesis, and sensory disturbance of the lower left extremity prompted us to carry out imaging studies of the spinal cord, which revealed multiple intradural, extramedullary mass lesions at the thoracic and lumbosacral spinal level. The tumours were histopathologically diagnosed as spinal seeding of the clival chordoma with high proliferative potential (Ki-67 labelling index of 8.4%). Interpretation. As long-term local control of skull base chordoma appears to be improving by the introduction of skull base surgical techniques and adjuvant radiotherapy, spinal intradural seeding might emerge as a potential complication. Close observation and timely imaging studies for spinal seeding of skull base chordoma would be required in long-term postoperative follow-ups, particularly for those patients with highly proliferative tumours.