🦴 “Onion Skin” Appearance – Important Oncology Question

This is a frequently asked radiology and oncology question in nursing and medical entrance exams.

✅ Correct Answer: (a) Ewing’s Sarcoma

Explanation:
The “onion skin” appearance refers to a layered periosteal reaction seen on X-ray. It looks like multiple concentric layers around the bone, similar to the layers of an onion.

This characteristic finding is classically seen in Ewing’s Sarcoma, which is a malignant bone tumor commonly affecting children and adolescents.

It usually involves the diaphysis of long bones and may present with pain, swelling, and sometimes fever.

Why are the other options incorrect?

(b) Rhabdomyosarcoma → A malignant tumor of skeletal muscle; it does not produce an onion-skin periosteal reaction.

(c) Primitive cell tumor → This is a broad term and not specifically associated with onion-skin appearance.

(d) Wilms tumor → A kidney tumor seen in children; unrelated to bone periosteal reactions.

Exam Trick:
Onion skin on X-ray → Think Ewing’s Sarcoma (Child + Bone tumor + Layered periosteal reaction).

💚 Exam Objective Nursing – Asha D
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