BMJ Case Reports 2017; doi:10.1136/bcr-2017-220801
  • Rare disease

The entrapped twin: a case of fetus-in-fetu

Open Access
  1. Norliana Jaafar
  1. Department of General Surgery, Sultan Abdul Halim Hospital, Sungai Petani, Malaysia
  1. Correspondence to Dr Rashide Yaacob, edie14770{at}
  • Accepted 24 August 2017
  • Published 23 September 2017


Fetus-in-fetu (FIF) is a rare entity in which malformed parasitic twin grows inside the body of its twin. It is most commonly presented with mass in the abdomen. We present a case of a 15-year-old boy who presented with abdominal mass since infancy. Radiological investigations are suggestive of FIF. Intraoperatively, malformed fetus in a sac was found and excised. Postoperatively the patient recovers well and was put on follow-up.


  • Contributors RY: gave the idea for the article; guarantor. AZM, DZHAJ and NJ: performed literature review. All authors: wrote the article and identified and managed the case.

  • Competing interests None declared.

  • Patient consent Guardian consent obtained.

  • Provenance and peer review Not commissioned; externally peer reviewed.

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:

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