Curettage of biopsy-diagnosed grade 1 periacetabular chondrosarcoma

Intralesional excision of intraosseous grade 1 periacetabular chondrosarcoma may seem an attractive alternative to the current recommendation of joint-sacrificing, en bloc resection. We report eight patients who initially underwent this treatment to identify if local tumor control can be achieved consistently. All patients had a percutaneous biopsy that was interpreted as grade 1 chondrosarcoma. The final histology after curettage indicated Grade 1 chondrosarcoma in five patients, Grade 2 in two, and dedifferentiated chondrosarcoma in one. Three of the five patients with true grade 1 chondrosarcoma have been free of disease at a median followup of 108 months. The other two patients with grade 1 chondrosarcoma on the curettage specimen recurred as higher-grade tumors. Three patients died of high-grade chondrosarcoma at a median of 23 months (range 17-72 months). Overall, the majority of patients in this cohort had either a misdiagnosis or recurrence of higher-grade disease. Based on these observations, in the absence of a predictable method to identify the true intraosseous grade 1 chondrosarcomas of the pelvis, curettage must be undertaken with the understanding that a percutaneous biopsy may misrepresent the histologic grade and that curettage may result in a higher risk of recurrence.