According to Enneking system, not true regarding an active benign tumor is

Thick rim of reactive bone Thick rim of reactive bone is a feature of Latent benign bone tumors and not Active benign bone tumors. Active benign rumors have a thin rim of reactive bone. Enneking has staged benign and malignant musculoskeletal tumors to aid in treatment decision making and to allow comparisons of treatment methods. The stages of benign tumors are designated by Arabic numbers, and malignant tumors are designated by Roman numerals. Enneking staging of Benign tumors Benign tumors are staged as follows: stage 1- latent; stage 2- active; and stage 3- aggressive. Enneking staging of Benign tumors Stage 1 Latent Intracapsular Usually asymptomatic, frequently incidental finding Grows slowly and then stops. Remains static/ usually heals spontaneously Radiographic features: - well-defined margin with a thick rim of reactive bone - no coical destruction or expansion Do not require treatment as they do not compromise the strength of bone e.g. Nonossib,ing fibroma Stage 2 Intracapsular Active Actively growing lesions Can cause symptoms or lead to pathological fracture Radiographic features: - well-defined margins with a thin rim of reactive bone - may expand and thin the coex Treatment usually consists of extended curettage e.g. Aneurysmal bone cyst Stage 3 Extracapsular Aggressive Aggressive clinically and radiographically Radiographic features: - Tumor breaks through the reactive bone and possible the coex - Soft tissue mass may be present Metastasis may be seen in 5% Treatment consists of extended curettage and marginal or even wide resection Local recurrences are common e.g. Giant cell tumor Enneking staging of Malignant Musculoskeletal tumors (Musculoskeletal sarcomas) Musculoskeletal sarcomas are classified into 3 stages. Stage 1: Histologically low grade sarcomas Stage 11: Histologically high grade sarcomas Stage HI: Sarcomas which have metastasized Each category is fuher subdivided into Type A and Type B Type A: Intracompamental (lesions are confined to an enclosed tissue space e.g. a bone, a joint cavity or a muscle group within its fascial envelope) Type B: Extracompamental (lesions which extend beyond their compament of origin) Low-grade or Stage I lesions High-grade or Stage II lesions Well-differentiated Poorly-differentiated Few mitoses High mitotic rate Moderate cytological atypic High cell-to-matrix ratio Risk for metastasis is low