Aggressive osteoblastoma of ilium: Diagnosed on FNAC

Introduction: Aggressive osteoblastoma is a rare tumor which has a higher growth potential than conventional osteoblastomas and high risk of recurrence. Case Report: An aggressive osteoblastoma of ilium diagnosed on cytology which had three recurrences. Osteolytic lesion of hemate bone occurred in a 23­year­old patient. Tumor was excised and diagnosed as osteoblastoma on histopathology. First recurrence was managed with excision and implantation of rods, and bony chips from right iliac bone. Second recurrence was similarly managed by implantation of bony chips from the other iliac bone. Below elbow amputation was performed following third recurrence. After eleven months from the last surgery patient developed swelling of iliac bone and pulmonary metastasis. Conclustion: The case highlights the biological diversity of aggressive osteoblastoma and its potential for implantation at the site of surgery and distant metastasis. The case illustrates the difficulties which may be encountered in differentiating between benign and malignant form of osteoblastoma, and between aggressive osteoblastoma and osteosarcoma.