두개골에 발생한 골육종

초록

Osteosarcomas are malignant bone tumors, which commonly affect the long bones of young adults. Primary osteosarcomas of the skull are exceedingly rare. Osteosarcomatous transformation in fibrous dysplasia is unusual, too. In the review of the literature, among the malignant transformation in fibrous dysplasia, osteosarcoma was the most common type of tumor . The next most common were fibrosarcoma and chondrosarcoma. The malignant transformation usually developed in the third or fourth decade of life and the most frequent anatomic site were the craniofacial bones, the femur,, and the tibia. About 25% of patients had the previous history of treated local radiation. We experienced a case of osteosarcoma of the skull showing the pathologic findings of malignant transformation in the fibrous dysplasia. The patient was 28 year old man suffered from a headache. He intermittently complained of headache which aggravated 1month ago. Neurologic examination was unremarkable except for the mild hypoesthesisa in right V2 and V3. Neither past history of radiation nor polyostotic bony lesion was present. Brain MRI revealed a solid mass with multiple cystic components in right middle cranial fossa, measuring 3cm. This mass destroyed sphenoid wing with extension to the infratemporal fossa. It showed iso- intensity on T1WI and T2WI with good enhancement. Craniectomy and excision of tumor were performed. The tumor was mostly composed of cellular spindle cell sarcoma with destruction of skull bone. Small amount of extracellular osteoid matrix was directly produced by sarcomatous tumor cells. Some transitional area from this sarcomatous portion to less cellular benign fibrous dysplasia area. The fibrous dysplasia portion showed Chinese letter-like woven bone without osteoblastic rimming. After operation, chemotherapy was performed. However, 15 days after operation, the tumor rapidly recurred forming 4cm sized well enhancing mass at the same place.