Fetus in Fetu in the Scrotal Sac: Case Report and Literature Review

External fetus in fetu presenting in the second trimester: A case report and literature review

Fetus in fetu (FIF) is a rare congenital anomaly that originates from various sites of the host twin's body. The clinical manifestations of FIF are diverse and the location and size of FIF indicate the degree of threat, which may directly affect the prognosis. A 33-year-old woman presented at the hospital with an abdominal mass in her fetus. Prenatal ultrasound observed that mass included soft tissue, bone-like structures, and fluid. Immature cartilage, nerve tissue, muscle tissue, and glands in the parasitic fetus without signs of neoplastic lesions were reported by histological examination. CNV (copy number variation) and WES (whole exome sequencing) did not detect any abnormal mutations. FIF can continue to grow with gestational age or host infant growth. So complete resection is essential for improving the outcome of the host twin. It is also important that long-term follow-up is recommended to monitor any residual or recurrent cysts or malignancies.

Twin Fetus-in-Fetu: The Story of an Encaged Twin

Background: Fetus-in-fetu (FIF) features a monozygotic, diamniotic, parasitic twin enclosed within its host twin. Case report: An 11-month baby girl presented with an antenatal diagnosis of a retroperitoneal mass. Radiological findings suggested it to be a teratoma. The mass was excised in-toto, histological findings were consistent with fetus-in-fetu. Conclusions: FIF may not have identifiable vertebral bodies and limbs upon imaging. Organized organ systems help differentiate this from a teratoma.

Retroperitoneal fetus in fetu presenting in a male infant: A case report and literature review

Fetus in fetu (FIF) is a rare congenital disease caused by the abnormal development of monochorionic diamniotic twins that appears as a cystic mass containing fetus-like structures mainly in the retroperitoneum of infants. The clinical manifestations of fetus in fetu vary, but they mostly present at infancy, hence, it should be differentiated from a teratoma. Here, we report a case of an infant with fetus in fetu in the retroperitoneum. Enhanced computed tomography scans and three-dimensional images showed a huge mixed-density mass on the left side of the abdominopelvic cavity with patchy distribution of fat, intact bones, and soft tissue. The child underwent fetus in fetu resection under general anaesthesia. Histopathology confirmed that the mass contained skin, muscle, intestinal mucosa, bones and cartilage, nerves, muscles, fat, and bone marrow tissue.

Scrotal fetus in fetu in a newborn: A rare case report

Fetus in fetu is a rare phenomenon of infancy, separate from conjoined twins, teratomas, and acardiac twins. The pathogenesis is not well understood but has been theorized to originate from either the involution of a twin or the differentiation of a teratoma. While the majority of these are found in the retroperitoneum, the presence of a fetus in fetu within the scrotum is exceedingly rare. We present the diagnosis and management of a case of fetus in fetu in the scrotum of a newborn male including radiologic imaging and pathologic examination.

A fetus excised from the small intestinal mesentery of a neonate (fetus in fetu): a case report

Background

Fetus in fetu is a rare congenital anomaly. Its incidence is 1/500,000 births. So, pediatric surgeons may encounter this pathology only once or twice during their professional careers.

Case presentation

We present a rare case of a fetus extracted from the small intestinal mesentery of a healthy neonate who was explored after delivery. The extracted fetal mass included a fully differentiated skull and limbs with a celomic cavity. The fetal mass was supplied by a main feeding vessel branching from the superior mesenteric artery.

Conclusion

Fetus in fetu, despite being a rare variant, must be kept in mind when dealing with a neonatal abdominal mass showing bony parts on radiography.

A cohort of five cases with asymmetric conjoined twining and literature review

PURPOSE

Asymmetric conjoined twining (ACT) is a form of conjoined twining which is a rare malformation of monochorionic monoamniotic twin pregnancy. Most publications were single case reports. We reported a cohort of five cases with ACT from a single tertiary medical center and reviewed the case reports of ACT over the last decade to enrich the clinical research of this disease and summarized the clinical features of the disease.

METHODS

We reviewed five cases of ACT admitted in Tianjin Children's Hospital from 17 March, 2008, through 7 March 2017. The cohort was analysed from general information, imaging manifestations, separation surgery, histopathological findings, outcome and follow-up. We searched the English literatures on case reports of ACT over the past decade from the PubMed database and presented details about the clinical characteristics, treatment, and prognosis of all cases.

RESULTS

There were four males and one female in our cohort. Among the five cases, two parasites were located in epigastrium, two in rachis, and one in retroperitoneum (fetus in fetu, FIF). All of the parasites were separated successfully by operation in five cases and were confirmed to be ACT by histopathology reports. Four patients made an uneventful recovery except for one case of wound infection. All of them were doing well in follow-up. In the literature review, we found 41 cases of exoparasitic heteropagus twining (EHT) and 63 cases of FIF.

CONCLUSIONS

ACT is very rare and usually diagnosed by prenatal ultrasonography (US). Computed tomography (CT) and magnetic resonance imaging (MRI) examinations are essential imaging examinations before separation surgery to delineate the anatomical relationship between the autosite and the parasite. In general, the separation surgery of ACT is less complicated and the prognosis is better compared with the symmetric conjoined twining (SCT).

Prenatal and postnatal MRI imaging findings of intracranial parasitic fetus: a case report

Fetus in fetu (FIF) is an extremely rare anomaly. It is predominantly seen retroperitoneally in 80% of cases but can present at atypical sites like the skull, sacrum, scrotum and the mouth. We reported a rare case of intracranial parasitic fetus. We described the prenatal and postnatal MRI findings of the case. There was no obvious spinal signal on the imaging findings at 35 weeks of gestation. However, the postnatal MRI revealed spinal column signal at 5 months and 11 days.

Neonatal Malignant Disorders: Germ Cell Tumors

Germ cell tumors (GCTs) comprise a wide spectrum of benign and malignant tumors. Neonatal GCTs are predominantly teratomas (mature or immature), which are typically cured with surgery alone. Relapses are infrequent even in the setting of microscopic residual disease; therefore, negative surgical margins at the cost of significant morbidity are not recommended. In neonates with metastatic malignant disease or malignant disease for which upfront surgical resection is not feasible without significant morbidity, an initial biopsy followed by neoadjuvant chemotherapy and delayed surgical resection is recommended. Carboplatin-based regimens should be considered when chemotherapy is indicated.

First Case Report of Adnexal Fetus in Fetu

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.

A case report of fetus in fetu with an aorta-like structure visualized by contrast-enhanced CT

Fetus in fetu (FIF) is a rare congenital anomaly resulting from abnormal embyogenesis in monochorionic diamniotic twins and appears as a cystic mass containing fetus-like structures mainly in the retroperitoneum of infants. Although there is a theory that FIF is a highly differentiated teratoma, it is commonly distinguished from teratoma as a mass containing a vertebral axis with appropriate arrangement of limbs or other organs around this axis. Here we present a case of FIF with aorta-like structure visualized by contrast-enhanced computed tomography. A 5-day-old girl was pointed out a cystic mass in the abdomen by ultrasound examination. Abdominal contrast-enhanced computed tomography revealed a retroperitoneal cystic mass with spine- and limb-like bone structures and blood vessel-like elongated structures and it was confirmed as FIF by surgery. The presence of major vascular structures along the skeletal axis is clearly different from teratoma and suggests that it occurred as an embryo and underwent some stage of development. Our findings strongly support the monozygotic twin theory.

Perinatal diagnosis and management of oropharyngeal fetus in fetu: A case report

Fetus in fetu is an extremely rare congenital anomaly. We describe the perinatal diagnosis and management of a fetus with oropharyngeal and cervical fetus in fetu. High-resolution ultrasonography with 3-dimensional rendering can identify increased risks of airway obstruction in utero. Early identification allows a multidisciplinary team to be assembled for a scheduled ex utero intrapartum treatment procedure.

Impact of prenatal diagnosis of fetus-in-fetu

Fetus in fetu (FIF) is an extremely rare condition (1/500,000 live births) in which a fetiform structure is incorporated into the body of its twin. FIF can be a diagnostic dilemma due to its similarity to a teratoma, but identification of FIF is important for subsequent medical and surgical management. We compare two cases of fetal masses diagnosed on prenatal imaging that were later identified as FIF through further radiological, surgical, and pathologic evaluation. We use these cases to illustrate key pre- and postnatal features of FIF and highlight the benefits of prenatal detection and follow-up for postnatal management.

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

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.

Fetiform Teratoma in the Ovary of a 7-Year-Old Girl: A Case Report

BACKGROUND

Fetiform teratoma, a highly differentiated mature cystic teratoma resembling a fetus, is rare and typically found in the ovaries of women of reproductive age. In this report we describe, to our knowledge, the youngest case of ovarian fetiform teratoma.

CASE

A 7-year-old girl presented with acute abdominal pain. Radiological examinations revealed a 5.2-cm ovarian complex cystic mass with fetal-like components in favor of fetus in fetu and teratoma. After surgical removal, the mass resembled a fetus consisting of a head, two eye slits, two small upper limb projections, and hair. Pathology indicated mature cystic teratoma supporting the diagnosis of fetiform teratoma.

SUMMARY AND CONCLUSION

Although not commonly found in children, fetiform teratoma must be considered in the diagnosis of a child who presents with an adnexal mass resembling a fetus.