Pathophysiology, classification, diagnosis, treatment, and prognosis of rhabdomyosarcoma, the most common malignant orbital tumor in children

 

Rhabdomyosarcoma is the most common primary malignant orbital tumor in children, originating from mesenchymal cells that would normally differentiate into striated muscle. It accounts for approximately 5% of pediatric malignancies and 2–4% of orbital masses.

🔹 Epidemiology & Features

• Median age: 7–8 years, mostly diagnosed before age 6
• Clinical signs: Rapidly progressive, painless proptosis, lid swelling, ptosis
• Lesion often located in the superonasal quadrant of the orbit
• May mimic chalazion or allergic eyelid edema, delaying diagnosis

🔹 Histologic Subtypes

• Embryonal: Most common, seen in infants/toddlers, good prognosis
• Alveolar: Highly metastatic, poor prognosis
• Pleomorphic: Rare, best prognosis
• Botryoid: Grape-like appearance, often arises in mucosal tissues

🔹 Diagnosis & Treatment

• Urgent biopsy required for confirmation
• Treatment includes surgical resection, radiotherapy, and chemotherapy
• Embryonal subtype is highly radiosensitive
• Survival beyond 2 years post-treatment implies cure
• If relapse occurs, average survival time is ~12 months

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📋 Rhabdomyosarcoma Summary Table (English)

CategoryDetails

Typical Age	7–8 years (mostly under 6)
Key Symptoms	Painless proptosis, sudden lid swelling, ptosis
Common Location	Superonasal orbit
Differentials	Chalazion, allergic swelling, orbital cellulitis
Histologic Types	Embryonal, Alveolar, Pleomorphic, Botryoid
Treatment	Surgery + Radiotherapy + Chemotherapy
Prognosis	Good if caught early; 2-year survival suggests cure