Table 1.
Clinical information about cases with dedifferentiated chondrosarcoma.
Fig 1.
The distribution of age and location in 23 patients with dedifferentiated chondrosarcoma.
(A) Age distribution. (B) Location distribution.
Fig 2.
Dedifferentiated chondrosarcoma of the left distal femur in a 73-year-old man (Case 4).
(A,B). Anteroposterior and lateral radiographs demonstrated chondral matrix mineralization, showing a low-grade chondral tumor but no signs of cortical destruction. (C). CT showed permeating cortical destruction. (D). Fat-suppressed axial T2-weighted image showed extra-osseous soft tissue with reduced signal intensity, prompting a dedifferentiated component. (E). Enhanced MRI showed punctate, ring or septal enhancement in the intraosseous chondral tumor component and heterogeneous evident enhancement in the extra-osseous dedifferentiated component.(F). Photomicrograph (HE staining X40) showing the biphasic pattern of low grade chondrosarcoma and high grade osteosarcoma. This patient underwent preoperative and postoperative chemotherapy; however, tumor necrosis of the lesion was only approximately 60% on histology. One year later, the patient suffered from lung and multiple organ metastasis and died after five months.
Fig 3.
Dedifferentiated chondrosarcoma of the left pelvis in a 59-year-old woman (Case 12).
(A). Anteroposterior radiograph demonstrated unilaminar benign periosteal reaction and low-grade chondrosarcoma. (B).CT showed expansive osteolytic bone destruction with typical chondral matrix mineralization and extra-osseous unmineralized soft tissue a mass cluing dedifferentiated component. (C). Fat-suppressed coronal T2-weighted image showed clear demarcation between reduced signal intensity (dedifferentiated component) and chondral signal intensity. The preoperative needle biopsy was accurate based on MRI.
Fig 4.
Dedifferentiated chondrosarcoma of the right pelvis in a 58-year-old man (Case 15).
(A). Anteroposterior radiograph demonstrated osteolytic bone destruction and a soft tissue mass without chondral or osteoid matrix mineralization. (B). CT showed punctate chondral matrix mineralization in the intraosseous medullary cavity, which might be high-grade chondrosarcoma. (C). Fat-suppressed coronal T2-weighted image showed a clear demarcation between predominant reduced signal intensity (dedifferentiated component) and chondral signal intensity. (D). Pathological section (HE X40) showed feature of the low grade chondrosarcoma and high grade malignant fibrous histiocytoma.
Fig 5.
Dedifferentiated chondrosarcoma of the left proximal tibia and fibula in a 49-year-old woman (Case 9).
(A).CT showed a flocculent shaped chondral matrix mineralization with marginal irregular shaped ossification and a soft tissue mass (B). Fat-suppressed coronal T2-weighted image showed heterogeneous signal intensity.
Table 2.
Evidence of tumor biphasic nature.
Table 3.
The histological grade of cartilage component and subtypes of dedifferentiation in 23 patients.
Fig 6.
Kaplan-Meier survival curve for 23 cases.
(A) The overall median survival time was nine months. (B). Overall survival time for cases in the appendicular bone compared with those in the axial skeleton; the difference is significant. (C). Overall survival time for cases with wide or radical surgical margin compared with inadequate margin; the difference is significant. (D). Overall survival time for cases pre- or post-chemotherapy compared to those without; the difference is not significant. (E). Overall survival time for cases with local recurrence compared to those without; the difference is not significant. (F). The survival curve for cases with lung metastasis at initial diagnosis compared to those without; the difference is significant.