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Primary malignant sacrococcygeal tumours: reasons for diagnostic delay.

Primary malignant sacrococcygeal tumours are relatively rare and difficult to detect. In our series of nine cases there were five sarcomas, two chordomas, one lymphoma and one myeloma. The tumours were from 5 to 16 cm in diameter when detected. The patient delay varied from 2 to 12 months, the doctors' delay from 2 to 6 months. The radiological method leading to the diagnosis was plain film in four, CT in three, tomography in one, and myelography in one. CT showed especially the soft tissue involvement. In four cases, the tumour was not visible on the plain film. The tumour was palpable per rectum in three cases. Our experiences show that many sacrococcygeal tumours are missed in a plain X-ray. Tomography and CT produce the most useful diagnostic information. CT and MRI are replacing conventional tomography. We believe that CT examinations of the sacrococcygeal region should be performed when symptoms suggest a tumour to be present.