Fetus-in-fetu: report of a case

MicroRNA expression profiles in non‑epithelial ovarian tumors

Ovarian germ cell tumors (OGCTs) and sex cord stromal tumors (SCSTs) are rare gynecologic tumors that are derived from germ and stromal cells, respectively. Unlike their epithelial counterparts, molecular pathogenesis of these tumor types is still poorly understood. Here, we characterized microRNA (miRNA) expression profiles of 9 OGCTs (2 malignant and 7 benign) and 3 SCSTs using small RNA sequencing. We observed significant miRNA expression variations among the three tumor groups. To further demonstrate the biological relevance of our findings, we selected 12 miRNAs for validation in an extended cohort of 16 OGCTs (9 benign and 7 malignant) and 7 SCSTs by reverse transcription-quantitative polymerase chain reaction. Higher expression of miR‑373‑3p, miR‑372‑3p and miR‑302c‑3p and lower expression of miR‑199a‑5p, miR‑214‑5p and miR‑202‑3p were reproducibly observed in malignant OGCTs as compared to benign OGCTs or SCSTs. Comparing with benign OGCTs, miR‑202c‑3p and miR‑513c‑5p were more abundant in SCSTs. Additionally, we examined Beclin 1 (BECN1), a target of miR‑199a‑5p, in the clinical samples using western blot analysis. Our results show that BECN1 expression was higher in malignant OGCTs than benign OGCTs, which is concordant with their lower miR‑199a‑5p expression. This study suggests that these miRNAs may have potential value as tumor markers and implications for further understanding the molecular basis of these tumor types.

Mediastinal teratoma in a neonate with acute respiratory failure

Background: While teratomas account for the leading cause of germ cell tumors, the mediastinal teratomas represent one of the infrequent types of congenital germ cell tumors. Neonates with large mediastinal teratomas generally show severe respiratory distress, and the immediate surgical treatment is needed to alleviate their problems.

Objectives: Report clinical symptoms, diagnostic procedures, treatment option, and outcomes after the treatment for a neonate with a large mediastinal teratoma.

Methods: A 2-day-old female infant presented with acute respiratory failure diagnosed as mediastinal teratoma. It was followed with surgical treatment. The removed tissues were examined pathologically.

Results: The girl suffered an acute respiratory failure two days after birth. The chest radiography, echocardiography, and chest computerized tomography results showed the considerable size of the mediastinal teratoma. A median sternotomy was performed on the third day of infant life to remove the tumor without rupturing the capsule. Pathological diagnosis was germ cell tumor. Clinical follow-ups reported no complication.

Conclusion: The successful management of a neonate with large mediastinal teratomas was presented. Immediate detection and proper treatment of the large mediastinal teratoma in a neonate was most important to decrease the morbidity and mortality of the infant.

Cells derived from iPSC can be immunogenic - yes or no?

The induced pluripotent stem cells (iPSCs), derived by ectopic expression of reprogramming factors in somatic cells, can potentially provide unlimited autologous cells for regenerative medicine. In theory, the autologous cells derived from patient iPSCs should be immune tolerant by the host without any immune rejections. However, our recent studies have found that even syngeneic iPSC-derived cells can be immunogenic in syngeneic hosts by using a teratoma transplantation model (Nature 474:212–215, 2011). Recently two research groups differentiated the iPSCs into different germ layers or cells, transplanted those cells to the syngeneic hosts, and evaluated the immunogenicity of those cells. Both of the two studies support our conclusions that some certain but not all tissues derived from iPSCs can be immunogenic, although they claimed either “negligible” or “lack of” immunogenicity in iPSC derivatives (Nature 494:100–104, 2013; Cell Stem Cell 12:407–412, 2013). To test the immunogenicity of clinically valuable cells differentiated from human iPSCs are emergently required for translation of iPSC technology to clinics.

Prenatal diagnostic clue for fetus in fetu

The purpose of this paper is to define a prenatal diagnostic clue for fetus in fetu (FIF) based on the characteristic findings of four FIF cases studied by the authors. A retrospective analyses of prenatal ultrasonography (US), postnatal US, computed tomography (CT) scans and operative findings were carried out on each of the four FIF cases collected from a multi-center. Prenatal US findings for each of the four cases showed a fluid-filled sac with a solid portion "floating" within it. In addition, bony structures were found in the solid portion. In each of the four cases, the postpartum imaging studies were consistent with the prenatal US findings. Operative findings revealed a solid mass within a fluid-filled sac surrounded by a transparent membrane. The solid mass was connected to the membrane by a stalk. Histopathologically, the cells making up the sac were of the same type as those of the amnion, while the solid mass had the general characteristics of FIF. In conclusion, FIF can be suspected when prenatal US shows a solid mass with bony structures within a fluid-filled sac in a newborn.

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.

The Ex Utero Intrapartum Treatment (EXIT) procedure used for airway control in a newborn with cervical fetus in fetu: a rare case

Fetus in fetu is a condition in which there is a monozygotic diamniotic fetus encased within the body of its larger more developed twin. We report a case of airway obstruction in a full-term fetus caused by fetus in fetu. Prenatal ultrasound revealed a large cervical mass compressing the neonate's trachea and esophagus. The Ex Utero Intrapartum Treatment procedure was utilized to secure the fetus's airway. Upon resection, a fetiform structure, covered by skin with vertebral tissue and two appendages was appreciated. To our knowledge, this is the first reported case of cervical fetus in fetu in the literature.

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.

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 with molecular analysis

This is the report of a case of fetus-in-fetu diagnosed in a 3-month-old boy and found to be located in the upper retroperitoneum. The entity was distinguished from teratoma by the presence of vertebral axis with limb buds. It corresponded to a diamniotic, monochorionic, monozygotic twin. Complete excision of the mass was performed. Radiological, histopathologic, and DNA fingerprinting studies performed on fetus-in-fetu specimen showed that the fetus was a monozygotic twin.

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.

Unusual presentation of heteropagus attached to the thorax

The endoparasitic twin is the most common form of asymmetric fetal duplication (heteropagus). A 2-month-old girl who had a parasitic right lower limb with axial skeleton, vertebral column, uterus, fallopian tube, ovary, and bladder implanted in the sternum region is described as another example of exoparasitic twin, the uncommon form of heteropagus. Unusually, dextrocardia was found in the autosite. This report emphasizes the even progression between the endoparasitic and exoparasitic forms of heteropagus.

Fetus in fetu: a case with complete umbilical cord and fetal sac

The authors present a retroperitoneal fetus in fetus in a 3-month-old girl. A 15-cm cystic mass with a monstrous fetuslike structure surrounded by a complete sac containing serous fluid was removed from the left retroperitoneal space. The draining vessel of the cystic mass was connected to the right renal vein of the host. The included fetus weighed 380 g. It had a well-developed umbilical cord, four extremities, head, buttock, and vertebral bodies with a meningomyelocele. The thoracic cavity of the included fetus had only a saclike foregut structure, but the abdominal cavity revealed a full length of intestine with a Meckel diverticulum, bilateral ovaries, urinary bladder, and cloaca with external opening. The cephalic end was composed of well-developed tooth germs, tongue and buccopharynx, mandible, maxilla, sphenoid bone, and salivary glands. Chromosomal study showed 46,XX with a normal G banding pattern. We report this case as an example of fetus in fetu with a complete umbilical cord and fetal membrane.

Fetus in fetu: molecular analysis of a fetiform mass

Fetus-in-fetu is a rare condition presenting as a calcified intra-abdominal mass in the newborn infant. Over 50 cases of fetus-in-fetu have been reported since 1800. Karyotype analysis in 8 cases and protein polymorphisms in 4 documented identical findings in the host and fetiform mass. We report a case of fetus-in-fetu in a newborn female including cytogenetic and molecular studies of both the host and mass. Genotypic information from 7 polymerase chain reaction (PCR) assays representing 4 chromosomes demonstrates heterozygous and identical alleles in the infant and fetus-in-fetu at all loci studied. A review of the literature is provided including a discussion regarding the impact of molecular data on present hypotheses of fetus-in-fetu pathogenesis.

Postnatal growth of fetus-in-fetu

A 6-month-old-boy who presented with an abdominal mass disclosed a well-formed fetus in the retroperitoneum. This mass was retrospectively noted at the age of 1 month. Comparison of two radiographic examinations done 5 month apart clearly demonstrated the enlargement of an included fetus in the bearer's abdomen. Our report of this rare condition focuses on the growth of the fetus-in-fetu detected by roentgenograms.

Fetus in fetu: a fetiform teratoma

Examination of a retroperitoneal fetus in fetu, diagnosed preoperatively, revealed previously unreported histologic findings in the vascular pedicle and membranous capsule that indicated that these structures are not "umbilical cord" or "amnion." These findings include nervous innervation of both structures and a well-defined lamina elastica interna and vaso vasorum in the artery of the vascular pedicle. Thus, strong support is provided for the theory that many examples of fetus in fetu are remarkably complex, well differentiated, highly organized teratomas. Additional arguments that favor the identity of fetus in fetu and teratoma are presented.