Fetus in fetu in the back.

1 of 2 DESCRIPTION An 11-year-old girl was hospitalised because of a large mass in her back ( fi gure 1 ). She was the second child in her family where there was neither twin pregnancy nor fetal malformation. The large mass has two parts where the upper part consists of a mammary gland and an attached upper limb including a scapular, humerus and two fi ngers, and where the lower part contains a thick-walled sac which endlessly secreted mucosal fl uid. There was not a clear cleavage plane between the autosite and the parasite. The anteroposterior spine radiograph showed congenital scoliosis anomalies ( fi gure 2 ), and the CT scan showed diastematorrhachia and diastematomyelia in the thoracolumbar region ( fi gure 3 ). Based on above-mentioned physical examination and imaging fi ndings, a diagnosis of fetus in fetu was thus made preoperatively. A surgical excision of the fetus in fetu was performed successfully. Histological sections of the excised sac specimen showed stratifyed squamous epithelium and digestive tract mucosa. Fetus in fetu is a very rare condition, with a reported incidence of one in 5000 000 live births. 1 It is a malformed parasitic monozygotic diamniotic twin that is found inside the body of the living child or adult. 2 Hoeffel et al 2 provide an excellent and very complete literature review of 88 cases including their own a case. The mass is located in the retroperitoneum in 80% of cases. It also occurs in other locations, such as Images in...