Age / Sex : 48 / F

Age / Sex : 48/F

Chief complaint : right knee pain for 2 years

chondrosarcoma

Discussion

Findings:
 There was a 2.6 x 1.7 x 4.0 cm mass with ring-and-arc calcification in the metaphysic of the right femur. MR images revealed a lobulated mass showing low signal intensity on T1-weighted images and high signal intensity surrounded by low-signal-intensity septa on T2-weighed images. Gd-enhanced T1-weighted MR images with fat suppression demonstrated peripheral and septal enhancement.

Differential Diagnosis: chondrosarcoma, enchondroma

Diagnosis: chondrosarcoma, FNCLCC grade 1

Discussion:
 The two most important factors of assessing a bone tumor are the location of the tumor and the age of the patient. The pattern of mineralization also can be a clue to make the diagnosis of a bone tumor. Calcification of chondral tissue often produces stippled, flocculent, or ring and arc mineralization. On the other hand, Bone-forming tumors have solid, cloud-like, and ivory-like mineralization, causing an opaque radiographic appearance. The radiography of this patient showed ring-and-arc calcification in the metaphysic of the right femur, indicating that the lesion is cartilaginous. The sclerotic areas represent chondroid matrix and the radiolucent component corresponds to the hyaline cartilage. In addition, the high signal intensity of the lesion on T2-weighed MR images reflected the high water content of hyaline cartilage. Differentiation of chondrosarcoma from enchondroma is often difficult clinically and radiologically. According to the previous studies, several factors—pain related to the lesion, deeper and more extensive endosteal scalloping, cortical destruction, soft tissue mass—suggest the diagnosis of chondrosarcoma rather than enchondroma.

References:

Radiographics 2003; 23: 1245

Radiographics 1998; 18: 1213