An unusual case of monozygotic epigastric heteropagus twinning

Brain malformations in diprosopia observed in clinical cases, museum specimens and artistic representations

BACKGROUND

Diprosopus is a rare malformation of still unclear aetiology. It describes a laterally double faced monocephalic and single-trunk individual and has to be distinguished from the variant Janus type diprosopus.

RESULTS

We examined seven double-faced foetuses, five showing true diprosopus, and one each presenting as monocephalic Janiceps and parasitic conjoined twins. Four of the foetuses presented with (cranio)rachischisis, and two had secondary hydrocephaly. Three foetuses showed cerebral duplication with concordant holoprosencephaly, Dandy-Walker cyst and/or intracranial anterior encephalocele. In the Janiceps twins, cerebral duplication was accompanied by cerebral di-symmetry. In the parasitic twins the cyclopic facial aspects were suggestive of concordant holoprosencephaly. In one of the true diprosopus cases, pregnancy was achieved after intracytoplasmic sperm injection. Whole-exome sequencing, perfomed in one case, did not reveal any possible causative variants.The comparison of our double-faced foetuses to corresponding artistic representations from the Tlatilco culture allowed retrospective assignment of hairstyles to brain malformations.

CONCLUSION

Brain malformations in patients with diprosopus may not be regarded as an independent event but rather as a sequel closely related to the duplication of the notochord and neural plate and as a consequence of the cerebral and associated craniospinal structural instabilities.

Heteropagus twins: six cases with systematic review and embryological insights

PURPOSE

Heteropagus twinning (HT) is a rare anomaly. Six new cases along with a systematic review are described.

METHODS

Six cases of HT managed at two tertiary care teaching hospitals over the last 26 years are described. A PubMed search with words: Heteropagus AND/ OR parasitic twins from 2001 to 2021 hit 183 articles. 36 were added from non-PubMed sources. Finally, 120 cases including 114 from 69 articles and 6 new cases were analysed.

RESULTS

Of the new cases, 2/6 had an antenatal diagnosis. Five were males. 4 autosites had omphaloceles. Split notochord and 2 parasites attached to a single autosite were encountered. 5/6 autosites survived. On systematic review, the most frequent variant seen was rachipagus (n = 50) followed by omphalopagus (n = 46). Limbs were reported in 75 cases. Congenital heart disease was seen in 17/120(14.2%) autosites. Omphalocele and meningomyelocele were the most common extracardiac anomalies in autosites. Weight along with the anatomy and position of heteropagus twins was a better determinant of the mode of delivery than weight alone. Mortality was reported in 12 cases.

CONCLUSION

Autosites in HT generally carry a good prognosis, however, final outcome depends mainly on associated major cardiac anomalies. Meticulous antenatal assessment and preoperative planning are of paramount importance.

LEVEL OF EVIDENCE

IV.

An unusual case of heteropagus: autosite with a complex cardiac malformation

Asymmetrical form of conjoined twinning (heteropagus) is an extremely rare event with an incidence of 1-2 million live births. The incomplete component of heteropagus, namely, parasite, usually consists of rudimentary organs. Therefore, the autosite component of heteropagus can be separated successfully. A wide spectrum of associated congenital cardiac malformations, which are usually minor, has been described in autosites. However, a single-ventricle heart anomaly in the autosite has been reported in a very few cases. We report an unusual case of heteropagus with a complex cardiac malformation. To the best of our knowledge, this is the third heteropagus case in the literature with a single-ventricle heart in the autosite.

The epigastric heteropagus conjoined twins

Conjoined twins are rare and are classified as symmetrical or asymmetrical, in which a member, the host (autosite), is near normal and bears the parasite, which is incomplete, smaller, and fully dependent for growth on it. This form of conjoined twins is referred to as heteropagus and when attached to the epigastrium of the autosite is called epigastric heteropagus. Only 44 cases of epigastric heteropagus twins have been previously reported in the world literature. We hereby report the successful separation of a pair of heteropagus twins.

Heteropagus (parasitic) twins: a review

Heteropagus, or "parasitic," twins are asymmetric conjoined twins in which the tissues of a severely defective twin (parasite) are dependent on the cardiovascular system of the other, largely intact twin (autosite) for survival. The estimated incidence of heteropagus twins is approximately 1 per 1 million live births. Isolated case reports comprise most of published work on this rare congenital anomaly. In the past, review articles have focused narrowly on one particular anatomical subtype of parasitic twin and/or on the anatomicopathology observed. Here, we present the epidemiology, proposed pathoembryogenic origins, anatomical abnormalities, management, and outcomes of the wide array of heteropagus twins described in the English language literature.

A case report of an omphalopagus heteropagus (parasitic) twin

Heteropagus twin refers to a type of conjoined twin in which an incomplete smaller (parasitic) twin is attached to and dependent upon an otherwise normal host twin. The majority of cases have complete or partial duplication of the pelvis and/or lower extremities. The case depicted herein is unusual in that only isolated case reports have described an attached amorphous mass without identifiable limbs.

Bizarre Presentation of Epigastric Heteropagus: Report of a Case

We report an unusual case of epigastric heteropagus in a female neonate. The parasite had a single lung as well as a liver, stomach, intestine, pancreas, ovaries, a single kidney, and a bladder. These visceral organs were located in the abdominal and pelvic space of the autosite, and the pelvic bone and lower legs of the parasite were fused with the respective organs in the autosite. The infant underwent operations to remove the central leg and some of the intra-abdominal organs of the parasite, but she must still undergo further surgery to remove the genitourinary organs and pelvic bones of the parasite, and repair her very abducted and rotated right leg.

Epigastric heteropagus twins: 3 case reports with review of literature

Conjoined twins are rare, heteropagus conjoined twins are rarer, and epigastric heteropagus conjoined twins are rarer still. It refers to unequal and asymmetrical twinning in which the dependant component (parasite) is smaller and attached to the epigastrium of the dominant component (autosite). We report 3 cases of epigastric heteropagus conjoined twinning. A review of literature is presented along with a discussion of possible etiopathogenesis.

Unusual case of epigastric heteropagus twinning

Asymmetrical conjoined twins or heteropagus twins are extremely rare. They are characterized by an incomplete component (parasite) that is normally smaller and dependent on the host (autosite). In cases of an epigastric heteropagus twin, the insertion occurs in the epigastrium. There are few reports of epigastric heteropagus twinning in the English-language literature. The authors report an extremely rare case of epigastric heteropagus twinning in which the parasite presented with head, thorax, and a rudimentary heart.

Three-dimensional ultrasound to differentiate epigastric heteropagus conjoined twins from a TRAP sequence

Twin reversed arterial perfusion sequence and epigastric heteropagus conjoined twins may appear similar antenatally. Three-dimensional ultrasound evaluated the relationship of a completely formed fetus and an adjacent second body consisting of a pelvis with 2 lower extremities, confirming the final diagnosis when two-dimensional ultrasound was unsuccessful. Three-dimensional ultrasound is useful in diagnosing epigastric heteropagus conjoined twins.

Asymmetric conjoined twins: atypical ischiopagus parasite

The authors report a rare case of asymmetric conjoined twins in which the incomplete parasitic twin was attached to the lumbar area of the autosite. The parasitic twin had well-formed bony pelvis, both lower limbs, partial genitourinary, and gastrointestinal tracts. The parasitic twin was excised, and the exomphalos was repaired.

Parasitic omphalopagus complicated by omphalocele and congenital heart disease

Conjoined twins occur in approximately one of every 50,000 to 200,000 births. Atypical or parasitic conjoined twins result from the embryonic death of one twin, which leaves behind body parts vascularized by the primary twin. Omphalopagus refers to conjoined twins joined at the level of the umbilicus. The authors report a case of atypical omphalopagus involving an acardiac, acephalic, parasitic twin and a host twin with a large omphalocele, transposition of the great arteries, and aortic coarctation. The authors briefly review reported cases of parasitic omphalopagus and emphasize the role of intensive neonatal care, preoperative planning, and staged surgical intervention in the successful management of complicated variants.

Epigastric heteropagus twinning

Conjoined twins is a very rare condition that represents, sometimes, a real challenge for pediatric surgeons. There is an even rarer situation, called heteropagus twinning, when one of the twins is not completely formed (parasite) and dependent of the well-formed one (autosite). The authors present a case of heteropagus twins in which the parasite was attached to the epigastrium of the autosite. In this situation, the separation procedure may be quite simple if a well-done anatomic study using x-ray, ultrasonography, computed tomography (CT) scan, magnetic resonance, and echocardiogram are performed. The precise knowledge of the anatomic variability and physiologic changes of both twins will help the surgeon make decisions like which surgical approach to use and the dissection tactic to be used. The pediatric surgeon also must be aware of the necessity to improvise during the operation.

Prenatal sonographic diagnosis of a twinning epigastric heteropagus

Epigastric heteropagus is a rare type of conjoined twinning which results from an ischemic atrophy of one fetus at an early stage of gestation. We present what we believe to be the first case diagnosed antenatally at 22 weeks' gestation. The pelvis and lower limbs of the ischemic fetus (the parasite) were attached to the epigastrium of the well-developed fetus (the autosite), which had a small omphalocele. Antenatal sonography provided an accurate diagnosis, enabling unnecessary abortion to be avoided.

An unusual case of epigastric heteropagus: parasite with a rudimentary heart

Parasitic or heterotopic conjoined twins are exceedingly rare, and these cases are referred to as "heteropagus" when there is a parasitic attachment in a nonduplicated fashion to any portion of the body. Epigastric heteropagus twinning refers to the attachment of the parasite to the epigastric region of the autosite. An unusual epigastric heteropagus case is presented with a rudimentary cardiopulmonary and also nearly complete gastrointestinal and genitourinary system of the parasite, and an organogenetic and vascular status of the previously reported cases are reviewed. The current case might be unique for the parasite having a cardiopulmonary development--although rudimentary--and this might be the reason that it has more complete organogenesis than the cases that have been presented previously in the literature.

Omphalopagus parasite: a rare congenital anomaly

Omphalopagus parasite is a very rare congenital anomaly. Presented here is a case in which an extra truncus was attached to an infant in the region of the epigastrium. The truncus had well-formed extremities, an abdomen, and a hypoplastic thorax. The infant had a small omphalocoele in addition to the truncus. Surgery performed in the neonatal period helped to achieve a successful separation of the truncus from the host.