Giant cell tumor of bone accounts for about 5% of all primary bone tumors in adults and is still one of the most obscure and intensively examined tumors of bone. This largely results from the lack of uniform clinical, radiographic, histological or morphological aspects that allow prediction of recurrence. Classified by the World Health Organization as “an aggressive, potentially malignant lesion”, the giant cell tumor of bone could give lung metastases, could undergo malignant degeneration or could have multicentric localization. It usually develops in long bones but can also occur in unusual locations. The common presenting symptom is increasing pain at the tumor site. Standard treatment ranges from curettage to wide resection, with reports of varying oncological and functional results. The recurrence rate is high during the first 2-3 years after surgery regardless of pre-operative tumor stage. Herein, we discuss the morphological, clinical, radiological, and therapeutic characteristics of this pathologic entity as well as its differential diagnosis.