Proximal epithelioid sarcomatous dedifferentiation in secondary chondrosarcoma in a known case of multiple osteochondromatosis

Abstract

Osteochondroma is the most common benign bone tumor. Approximately 15% of osteochondromas occur as multiple lesions. Multiple osteochondromatosis has a higher risk of developing chondrosarcomas, which are of low grade with good prognosis. About 10% of all chondrosarcomas may undergo dedifferentiated change, which has a poorer prognosis. Dedifferentiated peripheral chondrosarcoma developing within an osteochondroma is extremely rare. Dedifferentiation usually occurs in the form of osteosarcoma, malignant fibrous histiocytoma, fibrosarcoma, or rhabdomyosarcoma. We report a case of proximal epithelioid sarcomatous dedifferentiation in secondary chondrosarcoma in a 39-year-old male with multiple osteochondromatosis in bilateral arm. To the best of our knowledge, epithelioid sarcomatous dedifferentiation has not been described in the literature.

Small cell carcinoma of esophagus: Case report

“…In most of the cases, a chondrosarcoma arising from an enchondroma is of grade I. 4,9 The present case however had a high grade cartilaginous component along with dedifferentiation into fibrosarcoma and osteosarcoma. Other components which can be seen are malignant fibrous histiocytoma, leiomyosarcoma, angiosarcoma, rhabdomyosarcoma, lipoblastoma and very rarely an epithelioid sarcoma.…”

“…[1][2][3] However, when the chondrosarcoma is secondary to an enchondroma, the presentation is earlier, as seen in this case. 9 Pain, swelling, increase in size of an enchondroma or a recurrence after excision should alert the clinician to look out for a malignant transformation. In most of the cases, a chondrosarcoma arising from an enchondroma is of grade I.…”

“…Other components which can be seen are malignant fibrous histiocytoma, leiomyosarcoma, angiosarcoma, rhabdomyosarcoma, lipoblastoma and very rarely an epithelioid sarcoma. 1,9 The common sites involved by DDCS are femur and pelvis while humerus, ribs, spine tibia and upper extremities are rarer sites. 4 In a dedifferentiated chondrosarcoma, the cartilaginous component is usually seen within the bone and the dedifferentiated component exists outside in the soft tissue.…”

“…[1][2][3][4][5] Characterized by a sharp juxtaposition of a cartilaginous component with a high grade sarcomatous area, accurate pre-operative diagnosis of dedifferentiated chondrosarcoma(DDCS) requires a careful radiological assessment followed by a multipoint biopsy. [6][7][8][9] We present a case of secondary chondrosarcoma of humerus in a middle aged man with dedifferentiation into fibrosarcoma and osteosarcoma which was surgically resected but had a fatal outcome. This case highlights the importance of being alert while working up these cases.…”

Multifocal Giant Retroperitoneal Dedifferentiated Liposarcoma with dual heterologous dedifferentiation– a diagnostic and therapeutic challenge

“…[11] Chondrosarcomas and liposarcomas frequently showcase dedifferentiation into aberrant elements. [12] Though CDK4 and MDM2 positivity have been used to detect DDL, they alone are insufficient. Though numerous immunohistochemical markers have been studied in osteosarcoma and ChondrosarcomaChondrosarcoma including osteopontin, osteonectin and isocitrate dehydrogenase(IDH), SATB2, and galectin-1, the diagnosis is essentially based on the presence of malignant osteoid and cartilage.…”