Radiological findings of the chondroblastomas on the atypical sites of the skeleton system

Objective: To review the radiological findings of the chondroblastomas on the atypical sites of the skeleton system. Methods: We collected the total image data of 13 patients who were pathologically confirmed the chondroblastomas on the atypical sites of the bone system from the department of orthopedics in shanghai No. 6 hospital since 1991. Among all the patients, 11 eases were male and others were female. The range of age was 10-50 years and the average age of the patients was 26.2 years old. A retrospective analysis of radiological signs from different diagnostic imaging modalities was made. Results: X-ray examination was underdone on all case. On the plain X-ray films, all cases were lyric lesions. The radiolucent lesions were seen in 10 cases, mixed density in 3 cases. 10 cases manifested expansible contour. Eleven cases were performed computed tomography (CT) examination. On CT, there were visible calcification in 8 cases, sclerotic margin in 10 cases, internal septation in 4 cases. Soft masses could be seen in 3 cases. Magnetic resonance examination (MRI) was done on 5 cases. On T1 weighted images (T1WI) , the lesion was hypo and intermediate intense signal and heterogeneous hyperintense signal on T2 weighed images (T2WI). The fluid-fluid level and solid-fluid level were seen on 3 cases. On one post-contrast examination, the moderate enhancement was seen on the solid portion of the tumor and however, the obvious enhancement on the septation within the lesion. Conclusion: The radiological findings of the chondroblastomas on the atypical sites of the bone system were not suggestive. However, it could display some particular signs of the chondroid tumors such as calcification, septation, etc. To effectively apply the different imaging modalities can be helpful to make a right diagnosis before the operation. (authors)