Homer syndrome due to ectopic cervical thymus

Area of Science:

• Pediatric Neurology
• Thoracic Surgery
• Endocrinology

Background:

• Horner syndrome is a condition affecting the face and eye, often caused by neurological or vascular issues.
• Ectopic thymus, or thymus tissue found outside its normal location in the chest, is rare in infants.
• This case highlights a potential, though uncommon, cause of pediatric Horner syndrome.

Observation:

• A 9-month-old infant presented with classic signs of Horner syndrome.
• Initial magnetic resonance imaging (MRI) of the head and neck showed no abnormalities.
• Chest MRI revealed a mass consistent with ectopic cervical thymus.

Findings:

• The ectopic cervical thymus was identified as the probable cause of the infant's Horner syndrome.
• The absence of other identifiable causes supports the diagnosis.
• The infant's condition was managed non-surgically.

Implications:

• This case expands the differential diagnosis for Horner syndrome in infants.
• It underscores the importance of comprehensive imaging, including the chest, in pediatric neurological assessments.
• Early identification of ectopic cervical thymus can guide appropriate clinical management and follow-up.