Question

A child is brought to the orthopedics OPD with a deformity in the lower limb and hyperpigmented skin lesions. The x-ray of her thigh is shown below. What is the most likely diagnosis?

• A. Non-ossifying fibroma
• B. Fibrous dysplasia
• C. Paget's disease
• D. Osteogenesis imperfecta

Answer 1

The Correct Option is B

To determine the most likely diagnosis based on the given symptoms and x-ray, we analyze the details as follows:

• Deformity in the lower limb: This could indicate a structural abnormality in the bone, potentially related to growth or developmental issues.
• Hyperpigmented skin lesions: The presence of these lesions suggests a systemic condition rather than a purely orthopedic one, implying a link to a genetic or metabolic disorder.
• X-ray findings: Although the image isn't visible here, common x-ray features of fibrous dysplasia include a "ground-glass" appearance, well-circumscribed margins, and possible expansion of the bone.

Let's compare the conditions:

• Non-ossifying fibroma: Typically presents as a well-defined, sclerotic rimmed lytic bone lesion, commonly asymptomatic, and doesn't usually associate with skin changes.
• Fibrous dysplasia: Matches the symptoms well; characterized by fibrous tissue replacement of normal bone, resulting in deformities, often accompanied by skin pigmentation (Café-au-lait spots).
• Paget's disease: Involves abnormal bone remodeling, primarily in older adults, not typically accompanied by hyperpigmented lesions.
• Osteogenesis imperfecta: A genetic disorder causing brittle bones, often with blue sclera and not primarily hyperpigmented lesions.

Given the combination of lower limb deformity, hyperpigmented lesions, and characteristic x-ray features, fibrous dysplasia is the most likely diagnosis. This condition aligns well with all presented symptoms, including the bony deformity and skin manifestations.