A case report of hepatic fetus-in-fetu: Approach to diagnosis.

Multiple theories have been proposed about the pathophysiology of Fetus-in-fetu (FIF). The most widely accepted theory is abnormal embryogenesis in diamniotic monochorionic pregnancies, in which a malformed parasitic fetus is found within the body of a twin host. Hepatic FIF has been reported in almost 1% of FIF cases, with only 2 case reports being published in the literature. This article presents the third case report of intrahepatic FIF. Additionally, we review the role of radiology in diagnosing these cases and guiding their proper management. This case report supports the monozygotic twin theory of FIF and the diagnostic dilemma of FIF vs. teratoma can be solved through collaborative work between radiologists and pathologists.

A Unique Case of Eight Fetuses in a Single Fetu.

Fetus in fetu is a rare congenital anomaly in which a malformed parasitic twin is found within the body of a living child or adult. In this case report, a 1-day-old child presented with a large firm abdominal mass on the left side of the upper abdomen. Imaging studies misdiagnosed the mass as an intraperitoneal benign dermoid cyst displacing the bowel loops and internal viscera. A surgical resection was performed on 21 days of life, and pathology confirmed eight fetuses inside the cyst.

Prenatal diagnosis of well-developed fetus in fetu with spontaneous movement in a resource-limited setting: A case report.

Fetus in fetu (FIF) is a rare congenital anomaly characterized by the presence of a parasitic monozygotic twin encased within the body of its host twin. Because FIF is asymptomatic throughout pregnancy, it is mainly diagnosed in children with an abdominal mass after birth. In the case reported here, at 38-39 weeks of gestation, a 33-year-old woman (gravida 4, para 3) was referred for routine obstetric ultrasonography. Fluid accumulation was identified along with calcification resembling two well-developed legs and trunk with undifferentiated organs inside. Slight spontaneous movement of the legs was observed. The fetus was delivered based on the presumed diagnosis of FIF. Postnatal sonography and computed tomography (CT) supported the diagnosis. The neonate underwent surgical excision of the tumor and was discharged on the eighth postoperative day. Ultrasound can be used to provide accurate prenatal diagnosis of FIF. Early diagnosis is important to improve outcomes.

Neonatal Sacrococcygeal Fetiform Teratoma Containing Bowel: A Case Report.

A fetiform sacrococcygeal teratoma (homunculus) is a highly differentiated subgroup of mature cystic teratoma that resembles a malformed fetus. These tumors originate at the base of the coccyx and may vary in their intrapelvic and extrapelvic extent and location. It is important to differentiate this anomaly from fetus-in-fetu which has a higher degree of structural organization. A 5-day-old neonate presented with a type II sacrococcygeal fetiform teratoma. The mass contained both cystic and solid components. Upon surgical excision and coccygectomy, fully formed bowel was found inside the mass, as well as bones and other well-defined structures. The tumor was confirmed to be fully excised and no malignant or immature features were found on histopathological examination. The patient was last seen growing well with an alpha-fetoprotein of 3.5 µg/L, 14 months after resection.

Fetus In Fetu With Myelomeningocele.

Fetus in fetu is an uncommon medical anomaly characterized by the presence of a malformed fetus within the body of a living twin. Although the retroperitoneum is the most typical location, occurrences in the sacrococcygeal and dorsolumbar regions are rare. Ongoing debates center around its embryopathogenesis, debating whether it is a highly specialized teratoma or a result of parasitic twinning in a monozygotic monochorionic diamniotic pregnancy. Notably, distinguishing factors such as vertebral bodies and limbs are pivotal in discerning FIF from teratomas. Diagnostic imaging techniques are integral for preoperative diagnosis, with histopathological examination confirming the condition's presence.

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.

Fetus-in-Fetu: A Tale of the Trapped Triplets.

A 7-day-old male child presented with abdominal distention and jaundice. Radiological investigations revealed an encapsulated sac encasing three fetus-in-fetu (FIF) in the retroperitoneum. Laparotomy revealed a sac occupying almost the whole of the abdomen. The sac was stretching the duodenum and barely visible common bile duct, which were carefully separated. The rest of the bowel was displaced to the left. The sac containing three FIFs was excised intact. One of the fetuses was highly differentiated and had thoracic meningomyelocele, which has never been reported in FIF.

Fetus in Fetu: A Rare Congenital Anomaly Diagnosed Postnatally by Ultrasonography and MRI.

Fetus in fetu (FIF) is a rare congenital anomaly with two controversial theories regarding its embryogenesis. Although it is an extremely rare condition, it should be kept in mind as a differential diagnosis while evaluating children with abdominal calcification. Radiological findings on postnatal days 2 and 5 of a neonate with an antenatal scan showing an abdominal mass in the fetus are described here. Ultrasonography and magnetic resonance imaging (MRI) revealed the mass in which the contents favored a diagnosis of the FIF. Characteristic features of FIF on MRI have been less explored and knowledge regarding the same will be of immense help to the radiologist. Complete surgical excision followed by histopathology confirmed the diagnosis.

Case report and review of the literature: rare fetus-in-fetu presenting as oropharyngeal epignathus.

An epignathus is caused by a continuous spectrum of masses of the oral cavity or oropharynx ranging in its entity from mature teratoma to the exceedingly rare fetus-in-fetu. Due to its location, regardless of the entity, the occurrence of an epignathus is frequently associated with life threatening airway obstruction. Here we demonstrate a case of a fetus-in-fetu presenting as an epignatus. We describe its successful management and review the available literature. Early diagnosis and knowledge of the preoperative workup are essential to enable a multidisciplinary management. Once the airway is secured, surgical excision is the treatment of choice often resulting in a good clinical outcome and prognosis.

Ultrasound diagnosis of a retroperitoneal fetus in fetu: A case report.

Fetus in fetu (FIF) is a rare anomaly of diamniotic monochorionic twins, where a malformed fetus resides within the body of its twin. Most FIF occurs in the retroperitoneal region around the host spine and appears prenatally as a solid-cystic mass consisting of fetal-like structures. Imaging has an important role in the diagnosis of FIF. The present study reported a single case, a 45-year-old woman, with a teratoma in a third-trimester fetus diagnosed after prenatal ultrasonography (US), which showed a mass containing fetus-like echoes. FIF was considered after the US showed that the mixed solid-cystic retroperitoneal mass around the vertebral axis of the host fetus consisted of two separate masses, each containing distinct fetal visceral structures. One fetus was acardiac and the other parasitic fetus was visible with a weak heartbeat. Postpartum magnetic resonance imaging and ultrasonography (US) scans of the newborn showed a retroperitoneal cystic space-occupying mass with distinctive limbs and visceral structures. The pathological examination further confirmed the diagnosis of retroperitoneal FIF. Also, a prenatal US could detect FIF in utero. A cystic-solid mass containing long bones, vascular pedicles, or visceral structures around the vertebral axis of the host fetus in the US might suggest the possibility of a FIF.

The First Case of Fetus in Fetu in Nicaragua: The Management Experience of the Pediatric Neurosurgery Team.

Fetus in fetu (FIF) is a rare congenital anomaly of asymmetric monozygotic twins, where the parasitic twin develops abnormally inside the body of the host twin. In most cases, it is incorporated into the sibling's abdomen, which frequently presents as a retroperitoneal mass. Currently, at least 200 cases have been reported worldwide, being this the first case in Nicaragua. We describe a case of a male newborn, born via cesarean section, with a history of multiple congenital malformations observed via ultrasound examination. At birth, a mass is observed on its dorsum that impresses a skull, but without the presence of bones, with three limbs, two upper and one lower, with an outline located transversely on the pelvic girdle and the presence of two male genitalia with agenesis of the testicles and an accessory kidney. A preoperative diagnosis of FIF and spinal dysraphism was made by computed tomography (CT) and magnetic resonance imaging (MRI). They shared a spinal cord and had the presence of an open spinal defect type meningocele with aberrant roots. After the diagnosis and discussion, the multidisciplinary team proceeded to surgery to perform the separation of the twin (FIF). The subsequent anatomopathological examination revealed that the fetus was anencephalic and had reliable FIF characteristics. The resection was performed followed by the closure of the 430 mL meningocele and complete separation of the spine and the parasitic twin. We present the first case of fetus in fetu in Nicaragua.

Fetus-in-Fetu: A Differential Diagnosis of Neonatal Fetiform Encysted Abdominal Mass.

Fetus-in-fetu (FIF) is a rare embryological anomaly in which an encysted fetiform mass develops within the infant or adult host body. It mainly occurs intraabdominal. There are embryo-pathogenetic debates over whether it belongs to the spectrum of highly differentiated teratomas or is a parasitic twinning from a monozygotic monochorionic diamniotic pregnancy. The presence of vertebral segments and an encapsulating cyst can reliably distinguish FIF from teratoma. The diagnosis may be initially made by imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI), and a confirmatory diagnosis made by histopathology of the excised mass. Our center experienced a case of a male neonate presented after emergency cesarean delivery at 40-week gestation with the suspicion of an intraabdominal mass identified antenatally. Antenatal ultrasonography at 34 weeks gestation suggested the presence of an intraabdominal cystic mass measuring 6.5 cm with a hyperechoic focus. A follow-up MRI performed after the delivery showed a well-defined mass with the cystic formation in the left abdominal region with a centrally located fetiform structure. Vertebral bodies and long limb bones were visualized. The diagnosis of FIF was initially made preoperatively by the characteristic findings of imaging studies. Laparotomy was scheduled on day 6, revealing a large encysted mass with fetiform content. FIF should be considered a possible differential diagnosis of neonatal encysted fetiform mass. Routine antenatal imaging permits more frequent antenatal detection with earlier workup and management.

Case Report: A Giant Epignathus with a Well-Developed Skeleton of Head and Neck.

Epignathus is an extremely rare teratoma found in the oral cavity or oropharyngeal region of newborns, whose pathogenesis is poorly understood. We describe a giant epignathus arising from the oropharynx in a newborn. The giant tumor completely obstructed the airway of the newborn resulting in death. Histological and radiological examination of the tumor reveals the presence of a remarkably well-developed skeleton of the head and neck. A row of teeth, the axis and atlas, thyroid and salivary glands, trachea, and cerebral tissue are all detected within the tumor. These findings suggest that the epignathus is fetus-in-fetu which is considered a type 0 germ cell tumor in accordance with current literature.

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.

FOETUS-IN-FETU, A PAEDIATRIC RARITY IN AN INFANT AT IRRUA SPECIALIST TEACHING HOSPITAL, IRRUA, NIGERIA.

Introduction: Fetus in fetu is a paediatric rarity. It involves the presence of a mass resembling a fetus inside the body of a child or an adult. It is described as a twin growing inside the body of the other. It can be located in different parts of the body but commonly the retroperitoneum. It is usually benign. Case presentation: The patient was a 4 month old male infant who presented to the hospital with complaints of abdominal distention. The distention was noticed two months prior to presenting to our hospital. The distension was generalized and has been progressively increasing until presentation (1). There was no associated abdominal pain and no other abdominal symptoms. Conclusion: Treatment is by complete excision for histological examination.

Anesthetic Care During Exploratory Laparotomy and Excision of a Fetus-in-Fetu With a Combined General-Regional Anesthetic Technique Using a Caudal Epidural Catheter.

Fetus-in-fetu (FIF) is a rare, congenital anomaly involving the presence of one of a pair of twins within the body of the other. It is postulated that this pathology occurs during embryogenesis of a diamniotic-monochorionic twin pregnancy with unequal division of the blastocele, which results in monozygotic, monochorionic, and diamniotic twins of unequal sizes. Presentation as an abdominal mass during the neonatal period or infancy is most common, although late diagnosis during the adult years may also occur. We report a 1-day-old, full-term female neonate who presented for exploratory laparotomy and excision of a FIF. We present the use of a combined general-regional technique using caudal epidural anesthesia. The etiology, presentation, appropriate workup, and treatment of FIF are presented. Previous anecdotal reports of anesthetic care for excision of FIF are reviewed.

Fetus in Fetu: A Case of Vanishing Triplet Phenomena.

Fetus in fetu (FIF) is a rare congenital disorder in which a deformed fetus forms inside a normal one, mostly within the abdominal cavity. In this case study, we present a triplet pregnancy where one fetus was formed within a viable fetus. This was noted in prenatal imaging and upon delivery. Radiological investigations were conducted, including plain X-rays, abdominal computed tomography, and magnetic resonance imaging, and a preliminary case of FIF was diagnosed. Following this, surgical resection was planned and done soon after birth with histopathology confirmation of diagnosis, and it revealed no evidence of somatic malignancy. Currently, the patient is in stable condition and is being followed up with serial ultrasound imaging with alpha-fetoprotein levels to detect recurrence.

Is Fetus in Fetu a Reason for Vascular Anatomy Changes in the Host?

Fetus in fetu (FIF) is a rare congenital anomaly. Anomalies of inferior vena cava (IVC) in the host are rare and not reported in the literature. In this case report, the surgical management and the findings of a rare vascular anomaly of IVC in a 10-month-old male child with FIF are discussed. This case highlights the importance of antenatal ultrasonogram in the detection of FIF and to diligently look for structural anomalies of IVC in the host in such cases.

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.

Case Report: The Medical and Surgical Management of an Infant With Extreme Prematurity and Fetus-In-Fetu.

Fetus-in-fetu (FIF) is a rare congenital anomaly where a parasitic twin is within the body of a host twin. FIF is reported to occur in 1:500,000 live births. Herein, we report the first case of the medical and surgical treatment of a FIF patient who was born with extreme prematurity at 25-weeks gestation. With the multi-disciplinary coordination of neonatology, surgery, and interventional radiology, the patient was able to achieve a window of medical stability 4 weeks after birth. A decision was made at that time to proceed with an intra-abdominal and perineal resection of the FIF. The FIF was successfully resected and the patient was able to recover from the operation, with eventual discharge from the NICU. In conclusion, extreme prematurity and FIF may be amenable to surgical resection and a multi-disciplinary approach is crucial to achieve the desired outcome.