Chondrosarcoma

CLINICAL HISTORY

52-year-old man presents with anterior chest pain.

FINDINGS

Figure 1 shows a left chest wall mass arising from the anterior aspect of the third left rib without evidence of extension into the lung parenchyma. A 13-mm stalk (arrow) attaches to the mass at the neck of the third rib with a soft tissue component. Within the mass, there is also heterogeneous calcification. Figure 2 shows increased uptake at the left third anterior rib associated with an exophytic soft-tissue  (arrow) uptake. There was no other abnormal uptake to suggest metastasis.

DIAGNOSIS

Pathological evaluation revealed a grade 1 (of 3) well-differentiated chondrosarcoma arising in the background of a long-standing calcified enchondroma of the anterior aspect of the left third rib.

DIFFERENTIAL DIAGNOSIS

Differential diagnosis of a rib mass includes osteosarcoma, osteochondroma, osteoblastoma, enchondroma, and osteoid osteoma. Other possibilities include Ewing's tumors (pediatric patients), peripheral neuroectodermal tumors, malignant fibrous histiocytoma, Paget's disease, giant cell tumor, aneurismal bone cyst, metastases, multiple myeloma (plasmacytoma), and lymphoma.

DISCUSSION

Chondrosarcomas are malignant cartilaginous tumors. They can occur as primary tumors or they may arise from preexisting lesions such as an osteochondroma or enchondroma. They are more common in men and in adults over the age of 50. The most commonly affected sites include long tubular bones, the pelvis, ribs, and vertebrae.

Wide surgical resection is the treatment of choice due to the increased incidence of local recurrence and metastatic lesions with incomplete resection.

Case submitted by Shivani Gupta, M.D., and Robert Perone, M.D., both at St. Vincent's Medical Center in New York City.

References
1. Jeung MY, Gangi A, Gasser B, et al. Imaging of chest wall disorders. Radiographics 1999;19(3):617-637.

2. Murphey MD, Flemming DJ, Boyea SR, et al. Enchondroma versus chondrosarcoma in the appendicular skeleton: differentiating features. Radiographics 1998;18(5):1213-1237.

3. Fong YC, Pairolero PC, Sim FH, et al. Chondrosarcoma of the chest wall: a retrospective clinical analysis. Clin Orthop Relat Res 2004;(427):184-189.