Gastrointestinal bleeding in an 18-month-old Egyptian girl led to the discovery of an unusual mass inside her stomach. Further tests showed that it contained a malformed embryonic formation, in a very rare congenital condition medically known as “fetus in fetu”. A medical team successfully removed the mass, and the girl’s condition stabilised after surgery.
Endoscopy reveals mass inside girl’s stomach
Egypt’s Ministry of Higher Education and Scientific Research said the girl arrived at the National Liver Institute of Menoufia University, in the north of the country, suffering from gastrointestinal bleeding. She underwent medical tests and gastrointestinal endoscopy to identify the source of the bleeding, after which the endoscopy revealed a mass inside the stomach.
After the medical assessments were completed, the results showed that the mass contained a malformed embryonic formation, consistent with the condition known in English as “Fetus in fetu”. Doctors at the institute said in comments carried by Egyptian media that the endoscopy played a key role in discovering the mass, which was then assessed more extensively and referred to the surgical team.
The girl’s young age and the location of the mass led doctors to prepare a detailed plan for surgery involving several medical specialties. The operation ended with the removal of the mass and the embryonic formation inside it, while the girl’s condition remained stable and she underwent medical monitoring during the postoperative period.
How fetus in fetu develops
Fetus in fetu occurs when one of a pair of twins becomes enclosed within the body of the other during an early stage of embryonic development, then grows abnormally as an embryonic mass whose degree of formation varies from one case to another. The formation is not a complete or viable foetus.
The mass may contain varying parts resembling the spine, limbs or other organs. The presence of an organised axial structure, such as a spine and long bones, helps doctors distinguish the condition from some tumours that may have a similar appearance. The condition is thought to be associated with monozygotic twins, although the precise mechanism behind it remains under investigation.
In some cases, it can be difficult to distinguish the condition from highly differentiated teratomas, so diagnosis relies on a range of tests, including medical imaging and histological examination of the mass after removal. A recent systematic review covering 249 reports of individual cases and case series indicated that most cases appear during the first year of life.
The condition’s rarity and the difficulty of confirming it before surgery
The retroperitoneal area of the abdomen is the most common location for the mass, while the incidence is estimated at about one case per 500,000 live births. Cases vary in the degree of formation and composition of the mass, and the diagnosis may not always be clear before surgery.
Imaging tests help determine the nature of the mass and its relationship with surrounding organs, while complete removal and histological examination are essential to confirming the diagnosis.
Most published cases have had favourable outcomes, while the Egyptian girl’s case was distinguished by the mass being located inside the stomach and discovered following gastrointestinal bleeding.
