Intracortical osteosarcoma: Report of a case

Intracortical osteosarcoma is the rarest anatomic variation of osteosarcoma . There have been only 12 cases reported in the English-language literature . We present a case of osteosarcoma in an 18 year-old Taiwanese man that or iginated within the cortex of the tibial diaphysis. The initial radiograph revealed a lytic mass confined to the cortex, mimicking a benign bone lesio n. Histopathologic examination of the biopsy specimen showed an osteoblasti c osteosarcoma mingled with some fibroblastic foci. He underwent en bloc re section, and a metallic prosthetic intercalary stem was used to replace the larger bone defect. Adjuvant chemotherapy was administered before and afte r the operation. He was free of disease during 40 months of follow-up. A re view of all reported cases of intracortical osteosarcoma revealed that the initial method of treatment plays an important role in local recurrence and distant metastasis. Local excision and curettage leads to the worst result s. The outcomes of more recently reported cases have improved because of ea rly awareness of the possibility of malignancy and advances in chemotherapy . However, whether patients with intracortical osteosarcoma have a differen t prognosis from those with conventional osteosarcoma cannot be determined, because of the small number of intracortical osteosarcoma cases available for analysis.