Foetus-in-Foetu.

Area of Science:

• Medical Malformations
• Developmental Biology
• Pediatric Surgery

Background:

• Foetus-in-foetu is a rare congenital anomaly involving a parasitic twin within its host twin.
• Fewer than 100 cases are documented in medical literature, highlighting its rarity.
• This condition often presents as an abdominal mass in newborns, potentially mimicking other pathologies like germ cell tumors.

Observation:

• A one-day-old male neonate presented with an antenatal diagnosis of an abdominal mass.
• The mass was identified as cystic/solid, causing pressure effects on the left ureter and urinary bladder.
• Surgical exploration and excision were performed, leading to the confirmation of foetus-in-foetu.

Findings:

• Physical examination post-excision confirmed the presence of foetus-in-foetu.
• The parasitic twin was successfully removed from the host twin.
• The neonate's birth history was otherwise unremarkable.

Implications:

• Accurate prospective diagnosis of foetus-in-foetu can be significantly aided by advanced imaging techniques.
• Surgical excision remains the primary and recommended treatment for this rare condition.
• Understanding this anomaly is crucial for pediatric surgeons and radiologists managing complex neonatal abdominal masses.