Tumor cell seeding in the biopsy tract and its clinical significance in osteosarcomas.

Eleven cases (20%) involved microscopic tumor foci in the biopsy tract. The higher local recurrence rates (P = 0.005) and worse recurrence-free survivals ( P = 0.009) were observed in patients with tumor cell foci in the biopsy tract. Mitotic rate, tumor cell pleomorphism, and matrix production in main tumor foci were higher in cases with tumor seeding ( P = 0.047, P = 0.012, and P = 0.005, respectively) CONCLUSIONS: Tumor seeding in the biopsy tract is a fact in osteosarcomas. The higher local recurrence rates are more likely to occur in cases with tumor seeding.