Role of imaging in Chordoma with Histopathological correlation

Aims and Objectives: Chordoma are midline tumours originating from embryonic remnants of the primitive notochord. They are low-grade neoplasms, locally aggressive, slow-growing, but highly recurrent. Chordomas have 4 pathognomonic characteristics on plain film evaluation: expansion of the bone, rarefaction, trabeculation, and calcification. The usual radiographic pattern is lytic, with frequent calcification or sequestered bone fragments. CT scanning is essential, highly sensitive, and accurate for evaluating bony integrity, bone destruction, and calcifications or bone fragments within the lesion. Evaluation of the precise extent of the tumour and the degree of involvement of adjacent tissues is best performed by MRI. The aim of our study is to highlight the role of imaging in chordomas and to correlate imaging diagnosis with histopathological findings. Materials and Methods: The study was conducted over a period of one year on patients who came to MIMS general hospital with clinical and radiological suspicion of chordoma. This is a prospective study done on a total of 15 patients who were radiologically suspected as having chordoma and evaluated on Seimens 16 slice CT and Siemens essenza 1.5 tesla MRI with contrast. Results: In our study of 15 cases, most common age group was found to be 20-40 years and chordomas had slightly greater female predilection. Out of 15 cases, 9 were histopathologically proved as chordomas and the remaining 6 turned out to be false positive. Based on these results the sensitivity and specificity of CT and MRI in diagnosing chordoma is 100% and 60% respectively. Though there remains a question of controversy, in our study most common location is spheno-occipital region. Conclusion: In our study, we found out that both CT and MRI have good accuracy and are complementary to each other in diagnosing chordomas, however each one has certain superior characteristics over the other. Though radiological imaging plays an important role in diagnosing chordoma, histopathological examination is essential for confirmation. A rare presentation of chordoma with orbital extension was also included in our study, which was histopathologically proven. So, the possibility of chordoma should be suspected even if we found the lesion in an uncommon location, when typical radiological features of chordoma are encountered.