Fetus-in fetu in an Infant – A Case Report. Fetus-in-fetu
Iranian Journal of Pediatric Surgery,
Vol. 11 No. 2 (2025),
26 October 2025
,
Page 285 - 293
https://doi.org/10.22037/irjps.v11i2.47949
Abstract
Abstract:
Background – Fetus in fetu (FIF) is a rare pathological condition, mostly presenting as a fetiform, calcified abdominal mass in its living host which is usually a fetus or a newborn. Due to its rarity with an incidence of 1:500000, FIF is often missed in the differential diagnosis of an intra-abdominal mass in a newborn. Condition can be diagnosed in-utero as well as preoperatively in a newborn by imaging. FIF should also be differentiated from a teratoma because of the malignant potential of the latter. Surgical excision is almost always curative. The presence of vertebral segments and an encapsulating cyst can reliably distinguish FIF from teratoma. Condition can be diagnosed in-utero as well as preoperatively in a new born by imaging. Surgical excision is curative. Recurrence is extremely unusual.
Case presentation – An 8-month-old, full-term, male infant was brought with gradually increasing abdominal distension. Examination revealed a distended abdomen with a non-tender, irregular, firm mass in the right flank. Initial US imaging revealed the presence of a large foetoid tumor - like mass which was later confirmed as FIF on CT scan. There was evidence of a vertebral column along with bony appendages and formed organs. A laparotomy was done where sac was found to be loosely attached to the posterior abdominal wall. The entire mass was successfully removed. Baby made good recovery.
Conclusion - At the end of six months of follow-up, he is doing well with no new symptoms.
Keywords: Parasitic twin, teratoma, newborn.
- Parasitic twin
- teratoma
- newborn
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