Which imaging descriptor best fits unicameral bone cyst?

Which imaging descriptor best fits unicameral bone cyst?

• A. Osteosarcoma
• B. Chondrosarcoma
• C. Ewing sarcoma
• D. Radiolucent lesion with a single cavity

Answer: (D)

Unicameral bone cysts behave like simple, fluid-filled cavities within the bone. On imaging, the classic appearance is a radiolucent lesion that is well circumscribed and uni‑cameral (a single cavity), usually located in the metaphysis of a long bone in a child. This uniloculated, radiolucent pattern reflects the benign, non-aggressive nature of the lesion and its lack of internal septations or mineralized matrix. Because it is a non-aggressive process, it typically lacks features seen with malignant tumors: there is no aggressive cortical destruction, periosteal reaction, or internal calcifications. In contrast, the other conditions would more likely show such aggressive or distinctive features—osteosarcoma often has a sunburst or Codman triangle periosteal reaction; chondrosarcoma may show matrix calcifications within a lesion; Ewing sarcoma commonly presents with an onion-skin periosteal reaction and a more permeative or destructive pattern. Thus, a radiolucent, single-cavity lesion most closely fits unicameral bone cyst.

Unicameral bone cysts behave like simple, fluid-filled cavities within the bone. On imaging, the classic appearance is a radiolucent lesion that is well circumscribed and uni‑cameral (a single cavity), usually located in the metaphysis of a long bone in a child. This uniloculated, radiolucent pattern reflects the benign, non-aggressive nature of the lesion and its lack of internal septations or mineralized matrix.

Because it is a non-aggressive process, it typically lacks features seen with malignant tumors: there is no aggressive cortical destruction, periosteal reaction, or internal calcifications. In contrast, the other conditions would more likely show such aggressive or distinctive features—osteosarcoma often has a sunburst or Codman triangle periosteal reaction; chondrosarcoma may show matrix calcifications within a lesion; Ewing sarcoma commonly presents with an onion-skin periosteal reaction and a more permeative or destructive pattern. Thus, a radiolucent, single-cavity lesion most closely fits unicameral bone cyst.