Calcifications on the ring and arc pattern are typical for the chondroid matrix. The paravertebral mass included calcifications on the ring and arc pattern on CT images.
3,4. Extension into the surrounding soft tissue and cortical destruction of the adjacent bone are typical for chondrosarcoma
3-5. In our case, no obvious bone destruction wasattributed to the low grade of chondrosarcoma. The mass lesion was hypointense compared with muscle. Hypoatenuation may be associated with the cystic content of the hyaline cartilage component. The mass was heterogeneous isointense on T1-weighted MR images and heterogeneously hyperintense on T2-weighted MR images. The lobule structure of the tumor is due to the fibrovascular septa
6. Imaging findings were compatible with chondrosarcoma.
Chondrosarcoma grows slowly and symptoms develop slowly. The peak period of chondrosarcoma is 30-44 years old 3-5. The age of our patient was also 37 years old.
Clinical features of chondrosarcoma are non-specific. Pain is the most common symptom 3. Palpable soft tissue mass is seen in 28-82% of patients. Pathological fractures occur in 3-17% of patients 3,5.
Approximately 10% of chondrosarcomas are seen as spinal mass 2. It is mostly seen in the thoracic vertebra and more common in male 2. Patients are usually middle-aged and have back pain and/or neurological symptoms 7. The neurological symptom rate is 45% in patients with spinal chondrosarcoma 3-5. These paraspinal masses may include destructive lesions and calcifications 2.
In the differential diagnosis of chondrosarcoma, enchondroma comes first. It is difficult to distinguish them with imaging. However, pain is more often associated with chondrosarcoma. Soft tissue mass and cortical destruction are more likely for chondrosarcoma 8. Enchondromas are intramedullary cartilage neoplasms with benign imaging features. Enchondromas comprise lobules of mature hyaline cartilage. Cartilaginous lobules may contain calcification in the ring and arc pattern 9. Osteochondromas demonstrate medullary continuity and the cartilage cap 4. It may be thin or thick. Ring and arc calcifications may accompany. Chordomas can cause destructions in the vertebral corpus and may contain soft tissue mass. Calcifications are usually located in peripherally 4. Chordoma is the most common non-lymphoproliferative malignant tumor in adult vertebrae. The second most common is chondrosarcoma 4,5. Chondroblastomas are benign cartilaginous neoplasm and rare. It characteristically arises in the epiphysis of a long bone and rarely seen in the spine. Chondroblastoma is seen as well-defined lytic lesion with thin sclerotic rim 10. Bone metastasis is a less likely diagnosis. Because the patient has no primary tumor history and has a single lesion. Paraspinal nerve sheath tumors cause vertebral body scalloping. But calcification is seen rarely 11. Also, extramedullary hematopoiesis should be considered in differential diagnosis. Most common intrathoracic finding is a posterior mediastinal mass. These paraspinal masses may be either unilateral or bilateral and have smooth, sharply-delineated, often lobulated margins. Fat can be seen if chronic burnt out lesion is there but calcification is very atypical.
Although the patient's mass lesion contains coarse calcification, the lesion was mostly hypodense. This condition distinguishes chondroid neoplasms from osseous neoplasm (osteoblastoma, osteoid osteoma, and osteosarcoma) (4).
The differential diagnosis of posterior mediastinal masses is extensive. Although posterior mediastinum is a rare localization for chondrosarcoma, our patient had radiologic findings of chondrosarcoma. Ring and arc calcifications and the heterogeneous hyperintense T2 signal of the paraspinal mass should suggest chondrosarcoma. The clinical and radiological findings were consistent with chondrosarcoma. The mass lesion was totally excised and histopathologically chondrosarcoma was diagnosed.