Postnatal growth of fetus-in-fetu

Intra-abdominal retroperitoneal fetus in fetu: A case report

Fetus in fetu (FIF) is a rare abnormality where a vertebrate parasitic fetus develops inside the body of another normally developing fetus. It is distinct from teratomas, tumors composed of cells from multiple germ layers and have malignant potential. Symptoms of FIF arise from the mass effect, causing abdominal distension, feeding difficulties, and pressure effects on organs. FIF is commonly found in the retroperitoneal region but can also occur in other locations. It often includes certain organs such as the vertebral column, limbs, central nervous system, gastrointestinal tract, vessels, and genitourinary tract. Early diagnosis of FIF by ultrasound, computed tomography, and magnetic resonance imaging can improve patient outcomes. Surgical resection is the primary treatment approach, aiming to alleviate symptoms, and molecular analysis helps differentiate FIF from malignant teratomas. Regular follow-up is necessary due to the potential recurrence of teratomas.

Fetus in fetu in an adult woman

Fetus in fetu (FIF) is an extremely rare condition in which malformed fetus is found most commonly in the retroperitoneum of living twin. It occurs in about 1 in 500 000 live births and less than 200 cases have been reported in medical literature. We report FIF in a 17-year-old woman unlike other cases which were usually detected in early age and in male gender. This is the eighth case of adult FIF and the first case of FIF in adult woman worldwide. Preoperative diagnosis of FIF on CT was made and planned for exploratory laparotomy. The excised malformed fetus in a sac was proven as FIF on the basis of histopathological examination. In view to avoid such late presentation, early detection of FIF with radiological imaging in clinically suspected case is recommended. Surgical excision is the ideal treatment even teratoma is the differential diagnosis.

Revisiting fetus-in-fetu

Fetus-in-fetu is a rare congenital anomaly in which a malformed parasitic twin is found within the body of its partner. Less than 100 cases have been reported in published studies. Although it is a relatively benign condition, clinicians need to have a high index of suspicion for the associated complications that may arise. We report the case of an infant presenting with jaundice and steadily growing abdominal mass, who was diagnosed with fetus-in-fetu syndrome. We review the published studies and discuss the pathophysiology, complexities, and management options.

[Fetus in fetu: a case report]

Fetus in fetu is an abnormality secondary to abnormal embryogenesis in a diamniotic, monochorionic pregnancy. It is a rare pathological condition and fewer than 100 cases have been reported in the literature. We report a neonatal case which occurred in a girl who had been hospitalized since birth because of an abdominal mass. A conventional radiograph of the abdomen revealed a right mass containing calcifications, which displaced intestinal structures to the left. Abdominal ultrasonography and CT scan revealed a vascular and heterogeneous mass that contained numerous calcifications. The diagnosis of teratoma was suspected. After surgical excision, macroscopic and pathologic examination confirmed the diagnosis of FIF.

Fetus in fetu: two case reports and review of literature

Fetus in fetu is a rare disorder. Its embryopathogensis and differentiation from teratoma has not been well established. It is a parasitic twin of a diamniotic monozygotic twin. Here we report, two cases of fetus in fetu with review of literature. In case report 1, a 2-year-old boy was referred for asymptomatic lump in abdomen since birth. X-ray showed the mass in the abdomen with some calcification and fluid inside. CT scan reported a heterogenous mass in the retroperitoneum with bony malformation. CT showed presence of three vertebrae in it. After surgically excising the mass and opening the sac it showed presence of trunk and two limbs with one of the limbs having a nail. Histopathology showed presence of GI tract. In case report 2, 4 month female was found to have lump in the abdomen by housemaid while bathing. X-ray showed a soft tissue shadow while ultrasonography revealed cystic mass arising from right kidney. CT suggested cystic mass with calcification not arising from kidney. During exploration whole mass was excised and there was frank fetus inside it. Histopathology confirmed presence of four vertebral bodies with germ layers. Although fetus in fetu is rare condition, correct diagnosis using imaging can be made before surgery. Complete excision is curative.

Antenatal diagnosis of a third ventricular mass: fetus in fetu or teratoma?

BACKGROUND

Fetus in fetu (FIF) is a rare condition in medicine where an aberrant monozygotic twining results in inclusion of a degenerated fetus inside its twin bearer. Whereas FIF is generally defined as a fetiform vertebrate mass, teratoma is considered as a tumor composed of disorganized tissues derived from the three embryological layers. Recent data plead for a common origin and suggest a continuum between FIF and teratoma.

CASE HISTORY

We describe the case of an intraventricular mass diagnosed by prenatal imaging and associated with triventricular hydrocephalus. Surgical removal of a non-vertebrate mass covered by normal skin was performed when the child was 15 months old. Now aged of 30 months, the child continues to develop normally. Histological data were in favor of a FIF.

DISCUSSION

We discuss the diagnosis, pathogenesis, and prognosis in the light of data from the recent literature.

CONCLUSIONS

Aberrant monozygotic twining leading to inclusion of a degenerate fetus inside its twin bearer results in FIF or teratomas. Surgical removal represents the main treatment. Intracranial FIF remains an extremely rare congenital condition, with a favorable oncological prognosis; the developmental prognosis appears conditioned by the absence of other malformation, the small size of the lesion, and the early management of intracranial hypertension.

A girl with spina bifida, an extra leg, and ectopic intestinal loops--a "foetus in foetu" or a whim of the neural crest?

This article describes a girl with an extra leg attached to her lower back, combined with a spina bifida and a myelomeningocele. Despite lacking sensory or motor functions, the leg grew proportionately with the rest of the body. The bony structures were almost normal. A cross section showed fat tissue with some centrally situated blood vessels, nerve bundles, and muscular fragments. Proximally, an isolated colon loop was found. The extra leg and intestine respected the dorsal fascia, without connection with the peritoneal or retroperitoneal compartments. The finding is discussed with reference to existing hypotheses for limb formation.

Fetus-in-fetu: a rare entity

Fetus-in-fetu is a malformed parasitic monozygotic diamniotic twin that is found inside the body of the living child or adult. A 3-year-old male child presented with a retroperitoneal mass, which on radiological examination showed retroperitoneal teratoma. Pathological examination revealed fetus-in-fetu with partially developed vertebral column.

Fetus-in-fetu form of monozygotic twinning with retroperitoneal teratoma

One of the commonest defects of blastogenesis is monozygotic twinning resulting in separate or conjoint twins, the latter including a category of internal, "endoparasitic," or fetus-in-fetu twins. We report the third known instance of endoparasitic twinning associated with a benign teratoma at age 1. The host, twin, and teratoma were monozygotic by DNA analysis.

Ultrasound prenatal diagnosis of fetus in fetu

A case of fetus in fetu was diagnosed prenatally using ultrasound. The differential diagnosis between a fetus in fetu and a highly differentiated teratoma is discussed. The importance of prenatal diagnosis of fetus in fetu and the effect on subsequent management are described.

Fetus in fetu: a rare cause of a neonatal mass

Fetus in fetu is an unusual digression from the normal twinning process which often presents as a mass in neonates. Approximately 80 reports have been documented in the literature to date. The increasing use of routine obstetric ultrasound has identified more cases during the antenatal period. This allows more time for both the neonatology team and the parents to develop a coordinated treatment plan for the anticipated child. We report a case of a fetus in fetu which was first seen as a complex cystic mass during antenatal ultrasound at 21 weeks and was confirmed by subsequent imaging and surgical treatment shortly after birth.

Fetus in fetu: a case report and literature review

Fetus in fetu is a rare condition in which a fetiform calcified mass often is present in the abdomen of its host, a newborn or an infant. We report on a case of a 19-month-old girl whose plain abdominal radiograph, ultrasonography, and computed tomography scan revealed a mass in which the contents favor a fetus in fetu rather than a teratoma. The noncalcified vertebral column invisible on the radiographs was identified by the pathologist; therefore, the nonvisualization of the vertebral axis on radiography or on computed tomography scan does not exclude the diagnosis of fetus in fetu.

Fetus-in-fetu presenting as cystic meconium peritonitis: diagnosis, pathology, and surgical management

Fetus-in-fetu (FIF), a rare congenital anomaly, is a fetus incorporating the well-differentiated tissue of its twin. The authors describe a newborn who presented with massive abdominal distension and severe respiratory distress. Abdominal x-rays showed multiple calcifications. The diagnosis of meconium pseudocyst was made. At emergency laparotomy an irregular fetiform mass was found in the retroperitoneum lying within a fluid-filled amniotic sac. It contained a vertebral column, 10 limblike structures, and cranial and caudal ends, supporting the diagnosis of fetus-in-fetu. This case highlights several important points. FIF often is overlooked in the differential diagnosis of a newborn abdominal mass and, as in this case, may be confused with meconuim pseudocyst. FIF should be differentiated from a teratoma because of the latter's malignant potential. Because this diagnosis is not made until pathological analysis, all parts of the mass should be removed to prevent malignant recurrence.

Intrahepatic fetus-in-fetu: a case report and review of the literature

The authors report the third case since 1964 of fetus-in-fetu presenting at Red Cross Children's Hospital. A fetal liver abnormality was detected during routine antenatal ultrasound scan, and the postnatal diagnosis of an intrahepatic, multiple fetus-in-fetu was made with abdominal ultrasound scan, plain radiograph of the abdomen and computed tomography. The mass was removed surgically by hemihepatectomy when the patient was 4 months of age. Imaging and the macroscopic and microscopic appearances of the abnormality confirmed the diagnosis and amplified it to include an adjacent teratoma. Multiple small subcapsular and perimass vascular hamartomas were coincidentally discovered in the liver. Two of the 3 nodules within the amniotic-lined cavity of the intrahepatic mass individually comply with the accepted criteria for fetus-in-fetu, and the third nodule has the accepted features of a benign teratoma. The existence of multiple fetus-in-fetu and fetus-in-fetu combined with a teratoma, is recorded in the medical literature. The imaging as well as the macroscopic and microscopic features are illustrated.

Fetus-in-fetu: a case report and review of the literature

A unique case of intraperitoneal fetus-in-fetu attached to an ovary is presented. An asymptomatic newborn girl was found to have a mobile cystic mass in right side of her abdomen. Radiological investigations showed fetus-in-fetu. During laparotomy, an intraperitoneal fetus-in-fetu was found attached to right ovary and vascular pedicle to ovarian vessels. Only 79 cases of fetus-in-fetu have been reported, and this is the first such case attached to an ovary.