Background

There is an ambiguous and controversial line between fetiform teratoma and fetus in fetu (FIF) as differential diagnoses of a fetiform mass. Classically, the presence of vertebral column often with a relatively proper arrangement of other organs around the central axis favor the diagnosis of FIF over teratoma.

Case

Based on previously proposed criteria and the presence of vertebral organization in the radiological and histopathological assessment of the fetiform mass, we present an extremely rare case of adnexal FIF in a 10-year-old girl presenting with acute abdominal pain.

Summary and Conclusion

Whether FIF and fetiform teratoma are one entity or two, clinical discrimination for the choice of treatment seems to be unnecessary and the patient should be clinically followed for the probable malignant potential.

畸胎瘤是女性附件中的常见肿瘤。罕见地，肿块可能是高度组织的并且类似于胎儿。胎儿畸形畸胎瘤与胎儿胎儿之间存在着歧义性和争议性（FIF），作为对胎儿肿块的鉴别诊断，关于将FIF和胎儿畸胎瘤视为一两个实体仍存在争议。典型地，椎骨柱的存在通常相对于其他围绕中轴的器官相对适当地排列，相对于畸胎瘤更有利于FIF的诊断。但是，临床上对于选择治疗方法的区分似乎是不必要的，应该对患者进行临床随访以排除可能的恶性潜能。根据先前提出的标准以及在对胎儿样组织进行放射学和组织病理学评估时椎骨组织的存在，