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Year : 2012  |  Volume : 1  |  Issue : 3  |  Page : 174-176

Parasitic twinning - Varied presentations

Department of Pediatric Surgery, Niloufer Hospital, Institute of Child Health, Osmania Medical College, Hyderabad, A.P., India

Date of Web Publication15-Oct-2012

Correspondence Address:
Ramesh Reddy Kota
Plot 36, Snehapuri Colony, Nacharam, Hyderabad, Andhra Pradesh-500076
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/2277-8632.102445

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Over a period of 5 years, 4 cases of parasitic twins with varied clinical presentations were treated. One case presented with an accessory limb near gluteal region with caudal duplication. Two cases presented as localized mass lesions; one in the epigastrium and another in the gluteal region. Yet another case presented with accessory limb and a mass in the dorsal paraspinal region. Histopathology of these cases revealed presence of mature teratomatous elements and representation from varied tissues suggestive of parasitic twinning. Management of these cases needs to be tailored as per the anatomy and may need staged correction.

Keywords: Conjoined twinning, heteropagus, parasitic twin

How to cite this article:
Kota RR, Srirampur S, Kannaiyan L, Irfan G M, Sharab H, Rao S. Parasitic twinning - Varied presentations. J NTR Univ Health Sci 2012;1:174-6

How to cite this URL:
Kota RR, Srirampur S, Kannaiyan L, Irfan G M, Sharab H, Rao S. Parasitic twinning - Varied presentations. J NTR Univ Health Sci [serial online] 2012 [cited 2022 Jan 26];1:174-6. Available from: https://www.jdrntruhs.org/text.asp?2012/1/3/174/102445

  Introduction Top

Heteropagus type of parasitic twinning is a very rare event of conjoined twining. Conjoined twins are an uncommon complication of monozygotic twinning whose incidence is between 1 in 50,000 to 1,00,000 live births. [1] Heteropagus (parasitic) twinning refers to a rare type of conjoined twinning in which an incomplete small parasitic twin is attached to a normal host on whom it is dependent. [2] The normal host is known as an autosite. This rare form accounts for 5% of the conjoined twins. Parasitic twinning has a varied anatomy and morphology depending on the location and attachment to the host (autosite). [3] Presentation also depends on the extent of embryological damage incurred and the timing of the event. [4]

  Case Reports Top

Case 1

A one-and-half-year-old male child was presented with an asymptomatic hairy mass lesion in the upper abdomen since birth [Figure 1]. CT revealed multicystic calcified lesion. The mass was removed, which was seen adherent to the anterior surface of the liver. Gross examination of the specimen revealed rudimentary facial structures, cranium and spine, and a small and large bowel. Histopathology revealed a heteropagus twin with presence of 4-chambered heart-like structure [Figure 2].
Figure 1: Heteropagus twin on abdominal wall

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Figure 2: Four-chambered heart in parasitic twin

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Case 2

A 5-month-old male baby was presented with 2 lumps on the back since birth [Figure 3]. Clinical examination pointed them as a rudimentary limb and a thoracic meningomyelocele. Accessory limb-like structure was excised and thoracic meningomyelocele was repaired.
Figure 3: Rachipagus twin with meningomyelocoele

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Case 3

A 3-month-old male baby was presented with a mass in the gluteal region. On evaluation, it was diagnosed as a parasitic twin with limb-like structures and a rudimentary mucosa lined pit without any bony attachment. Wide excision was performed.

Case 4

A term female neonate was presented with an anorectal anomaly (absence of anal orifice) and duplication of external genitalia and an extra limb attached to gluteal region [Figure 4] and [Figure 5]. On examination, there was a rudimentary lower limb of 10 cm with digits, attached to the gluteal region and a skin-covered lumbar meningomyelocele. Proximal colostomy and excision of accessory limb was performed. Repair of meningomyelocele and correction of external genitalia are being planned through surgery at a later date.
Figure 4: Rachipagus twin with pelvic duplication

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Figure 5: Pelvic duplication showing the duplicated pelvis

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  Discussion Top

Conjoined twinning is considered as a form of duplication or doubling anomaly. The etiology though unknown, is generally considered to be due to an error in blastogenesis because of incomplete fission of a single zygote. Spencer et al. considered the embryogenesis of this anomaly to be due to the failure of complete division of a single zygote. [2] Logrono et al. stated that heteropagus twinning occurs due to fusion of 2 embryos prior to implantation. [5] It is also postulated that selective ischemic damage in utero, results in death and partial resorption of one of the twin which eventually will be a parasitic twin attached to the normal host. [6] In spite of these theories, the final etiopathogenesis of heteropagus twins remains enigmatic. There is a marked female predominance among diplopagus conjoined twins. But for unknown reasons, male predominance is seen in heteropagus (parasitic) twins. [7]

Epigastric heteropagus twins do not have bowel or bony continuity with the autosite. Most of them are acardiac, though a rare presence of rudimentary cardiovascular system is reported in epigastric heteropagus twins. [8] In case 1, the parasite was adherent to the liver and the histopathology revealed the presence of 4-chambered cardiac structure. O'Neil et al. had described that vascular pedicle to an epigastric heteropagus twin usually arises either from the falciform ligament or from the upper part of the trunk of the autosite. [9] Rachipagus parasitic twins are those, which arise dorsally near the vertebral canal or presumably near the vertebral arches. In several cases of rachipagus parasitic twinning, there is an associated spinal dysraphism as in cases 2 and 4. Rachipagus parasitic twins are considered to be a rare type of conjoined twinning, [10] and are usually associated with vertebral and CNS abnormalities at or near the site of union. [11] Caudal duplication is a rare entity in which structures from cloaca and notochord are duplicated to various extents. In the present collection, case 4, heteropagus twin was associated with caudal duplication.

  Conclusion Top

In conclusion, parasitic (heteropagus) twinning is a rare congenital anomaly with a varied presentation depending on the site of origin of the parasite and time of embryologic insult. It may be associated with anomalies of CNS, anterior abdominal wall defects and caudal duplication.

  References Top

1.Edmonds LD, Layde PM. Conjoined twins in the United States, 1970- 1977. Teratology 1982;25:301-8.  Back to cited text no. 1
2.Spencer R. Parasitic conjoined twins: external, internal (fetuses in fetu and teratomas), and detached (acardiacs). Clin Anat 2001;14:428-44.  Back to cited text no. 2
3.Chadha R, Lal P, Singh D, Sharma A, Choudhury SR. Lumbosacral parasitic rachipagus twin. J Pediatr Surg 2006;41:E45-8.  Back to cited text no. 3
4.Higgins KR, Coley BD. Fetus in fetu and fetaformteratoma in 2 neonates: An embryologic spectrum? J Ultrasound Med 2006;25:259-63.  Back to cited text no. 4
5.Logroño R, Garcia-Lithgow C, Harris C, Kent M, Meisner L. Heteropagus conjoined twins due to fusion of two embryos: Report and review. Am J Med Genet 1997;73:239-42.  Back to cited text no. 5
6.Spencer R. Theoretical and analytical embryology of conjoined twins: part I: Embryogenesis. Clin Anat 2000;13:36-53.  Back to cited text no. 6
7.Bansali M. Epigastric heteropagus twins: 3 case reports with review of literature J Pediatr Surg 2005;40:1204-8.  Back to cited text no. 7
8.Ozcan C, Ergün O, Güçlü C, Tümüklü M, Alper H, Erdener A. An unusual case of heteropagus: Parasite with a rudimentary heart. J Pediatr Surg 2000;35:1523-5.  Back to cited text no. 8
9.O'Neill JA Jr, Holcomb GW 3 rd , Schnaufer L, Templeton JM Jr, Bishop HC, Ross AJ 3 rd , et al. Surgical experience with thirteen conjoined twins. Ann Surg 1988;208:299-312.  Back to cited text no. 9
10.Mazzullo G, Monteverde V, Macrì F, Partanna S, Caracappa S. Incomplete caudal duplication in a puppy gross and radiological observations. J Small Anim Pract 2007;48:410-3.  Back to cited text no. 10
11.Nanni L, Perrelli L, Velardi F. Accessory lower limb in a newborn with multiple malformations. Eur J Pediatr Surg 1994;4:51-3.  Back to cited text no. 11


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]

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