Best Examination Tips: Medcase, Interesting Medical Cases and Pictures

  • Sunday, July 7th, 2013

Case 12/Picture 14 (29.12.2013.) Could you identify the medical condition in this baby girl?

one year old girl pregnant


This is a picture of “Fetus in fetu“.

“Fetus in fetu” is estimated to occur in 1 in 500,000 live births. An early example of the phenomenon was described in 1808 by George William Young. Fetus in fetu (or fetus in fetu) is a developmental abnormality in which a mass of tissue resembling a fetus forms inside the body. There are two theories of origin concerning “fetus in fetu”. One theory is that the mass begins as a normal fetus but becomes enveloped inside its twin. The other theory is that the mass is a highly developed teratoma. A fetus in fetu can be considered alive, but only in the sense that its component tissues have not yet died or been eliminated. Thus, the life of a fetus in fetu is akin to that of a tumour in that its cells remain viable by way of normal metabolic activity. However, without the gestational conditions in utero with the amnion andplacenta, a fetus in fetu can develop into, at best, an especially well differentiated teratoma; or, at worst, a high-grade metastatic teratocarcinoma. In terms of physical maturation, its organs have a working blood supply from the host, but all cases of fetus in fetu present critical defects, such as no functional brain, heart, lungs, gastrointestinal tract, or urinary tract. Accordingly, while a fetus in fetucan share select morphological features with a normal fetus, it has no prospect of any life outside of the host twin. Moreover, it poses clear threats to the life of the host twin on whom its own life depends. Fetus in fetu may be a very highly differentiated form of dermoid cyst, itself a highly differentiated form of mature teratoma. Fetus in fetu may be a parasitic twin growing within his or her host twin. Very early in a monozygotic twin pregnancy, in which both fetuses share a common placenta, one fetus wraps around and envelops the other. The enveloped twin becomes a parasite, in that his or her survival depends on the survival of his or her host twin, by drawing on the host twin’s blood supply. The parasitic twin is anencephalic (without a brain) and lacks some internal organs, and as such is almost always unable to survive on its own. As the normal twin has to “feed” the enveloped twin from the nutrients received over a single umbilical cord, he or she usually dies before birth.


1. George William Young (1608). “Case of A Foetus found in the Abdomen of a Boy”. Retrieved 2012-11-22.

2. Chua, JHY; Chui CH, Sai Prasad TR et al. (2005). “Fetus-in-fetu in the pelvis” (PDF). Annals of the Academy of Medicine Singapore 34: 646–9.

3. Grant P, Pearn JH (May 1969). “Foetus-in-foetu”. Med. J. Aust.1 (20): 1016–9. Cited here following Hoeffel CC, Nguyen KQ, Phan HT, et al.(June 2000). “Fetus in fetu: a case report and literature review”Pediatrics 105 (6): 1335–44.

4. “Journal of Medical Case Reports | Full text | Fetus in fetu : a case report”. Retrieved 2012-11-22.

5. Basu A, Jagdish S, Iyengar KR, Basu D (October 2006). “Fetus in fetu or differentiated teratomas?”. Indian J Pathol Microbiol 49 (4): 563–5.

‘Pregnant’ one-year-old girl has unborn twin’s foetus removed

Read more:

“A one-year-old girl has survived surgery to remove her unborn twin’s foetus from her swollen stomach. Kang Mengru was abandoned at birth and was taken in by a childless couple in Luohe City, in the central Chinese province of Zhenzhou. Within months, her stomach began to swell and superstitious neighbours began calling the little girl a ‘monster’ and gossiping that she was pregnant. Medical scans revealed Kang was actually carrying the parasitic foetus of her unborn twin in her belly. A doctor told Kang’s worried foster parents: ‘She will die unless she has the surgery immediately.’ After 10 hours of complex surgery to remove the foetus, Kang’s family have been told she can return home at the end of the month having made a full recovery. Chief surgeon Dr Zhang Xuedong told The Sun: ‘She will be able to go home at the end of the month, with her mother Wang Guihua and father Kuang Xiqing. ‘There was a very real risk of cardiac arrest. The pressure within the child’s chest and belly was very great but now she is out of danger.’ But Kang’s foster family had to rely on donations to be made to a fund set up by local government in order to pay for the surgery.”

Case 12/Picture 15 (06.01.2014.) Could you identify the medical condition in this baby girl?

1 year-old girl pegnant with parasitic twin Answer

This is a picture of “Fetus in fetu“, the same girl as in Case 12/Picture 14.

Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55

Tags: , , , , , , , , , , , , , , , , , , , , , , ,


There are no comments yet, add one below.

Leave a Comment

You must be logged in to post a comment.

Gynaecology / Gynecology

Services O&G Health