Spontaneous regression of severe acquired infantile hypothyroidism associated with multiple liver hemangiomas

Area of Science:

• Pediatric Endocrinology
• Neonatal Medicine
• Vascular Anomalies

Background:

• Congenital and postnatal hypothyroidism are critical conditions requiring timely diagnosis and management in infants.
• Infantile hepatic hemangiomas are common benign vascular tumors, typically resolving spontaneously.
• Thyroid hormone metabolism can be complex, influenced by various physiological and pathological factors.

Observation:

• A 9-week-old infant presented with severe hypothyroidism, necessitating a high L-thyroxine dosage.
• Multiple asymptomatic hepatic hemangiomas were identified at 6 months of age.
• The infant's hypothyroidism resolved as the hemangiomas involuted, allowing L-thyroxine cessation by age 3.

Findings:

• The infant's severe hypothyroidism was linked to increased type 3 iodothyronine deiodinase activity within the hepatic hemangiomas.
• This activity led to the consumption of thyroid hormones, causing 'consumptive hypothyroidism'.
• The condition highlights a direct impact of vascular tumor activity on infant thyroid hormone homeostasis.

Implications:

• This case underscores the importance of considering rare causes of hypothyroidism in infants, especially when standard treatment requires high doses.
• It demonstrates a direct clinical correlation between infantile hepatic hemangiomas and thyroid hormone dysregulation.
• Early identification and monitoring of such cases can lead to appropriate management and normal neurodevelopmental outcomes.