**Core Concept:** Osteochondroma is a benign bone tumor composed of cartilage and bone tissue. Malignant bone tumors, such as osteosarcoma, exhibit specific clinical signs during their development. Malignant osteosarcomas often arise from pre-existing benign tumors like osteochondromas.

**Why the Correct Answer is Right:** Osteochondromas are benign tumors that do not undergo malignant changes. The correct answer, D, represents the absence of malignant signs in osteochondromas. A malignant tumor, like osteosarcoma, would possess the signs mentioned in the other options, making them incorrect.

**Why Each Wrong Option is Incorrect:**

A. **Option A (Tumoral Necrosis):** Osteochondromas do not exhibit necrosis, which is a characteristic feature of malignant tumors.

B. **Option B (Local Invasion):** Benign tumors like osteochondromas do not invade surrounding tissues, whereas malignant tumors like osteosarcomas can invade nearby structures.

C. **Option C (Metastasis):** Benign tumors like osteochondromas do not spread to distant organs or tissues, while malignant tumors like osteosarcomas can form secondary lesions at other sites.

**Clinical Pearl / High-Yield Fact:** While benign osteochondromas are relatively common and often asymptomatic, it is essential to keep an eye out for malignant changes like osteosarcoma that could develop from these tumors. Early detection and prompt intervention are crucial for successful treatment outcomes.

**Correct Answer:** D. Tumoral Necrosis