## Core Concept
Osteosarcoma, also known as osteogenic sarcoma, is the most common type of primary bone cancer, characterized by the direct formation of bone or osteoid tissue by the tumor cells. It typically occurs in the metaphyseal regions of long bones, with the majority of cases arising in the distal femur or proximal tibia. Osteosarcoma is highly aggressive and has a tendency to metastasize, primarily to the lungs.

## Why the Correct Answer is Right
The correct answer, although not directly provided, needs to be evaluated based on common facts about osteosarcoma. Typically, osteosarcoma is known for its aggressive nature, peak incidence in adolescence, and association with certain genetic syndromes or radiation exposure. A correct statement about osteosarcoma would involve its clinical presentation, histological characteristics, or treatment modalities.

## Why Each Wrong Option is Incorrect
Without specific details on options A, B, C, and D, a general approach to evaluating incorrect statements about osteosarcoma is provided:

- **Option A:** If a statement claims osteosarcoma is most common in adults, it would be incorrect because osteosarcoma peaks in adolescence.
- **Option B:** If a statement suggests osteosarcoma primarily metastasizes to lymph nodes, it would be incorrect because osteosarcoma most commonly metastasizes to the lungs.
- **Option C:** If a statement indicates osteosarcoma is typically found in the shafts of long bones, it would be incorrect because osteosarcoma usually occurs in the metaphyseal regions.
- **Option D:** If a statement mentions that osteosarcoma is usually low-grade and rarely metastasizes, it would be incorrect because osteosarcoma is typically high-grade and has a high metastatic potential.

## Clinical Pearl / High-Yield Fact
A key point to remember is that osteosarcoma often presents with systemic symptoms such as weight loss and night pain, and it is diagnosed through a combination of radiography, MRI, and biopsy. The treatment involves neoadjuvant chemotherapy, surgery (often limb-salvage surgery), and adjuvant chemotherapy, significantly improving survival rates over the years.

## Correct Answer: D. Rarely metastasizes.