Poorly organized parasitic conjoined twins: report of four cases

Lipomatous Lumbar Mass with an Attached Digit and Associated Split Cord Malformation

Background:

A male infant was born with a digit attached to a skin-covered lumbar lipomatous mass and an underlying split cord malformation.

Methods:

Surgical removal of the mass was performed at four months-of-age. By this time the digit had grown a nail and imaging and histology showed ongoing development of articulated phalanges.

Results:

The lipomatous mass contained a long bone, a clavicle-and scapula-like structure and a variety of other mature germ layer derivatives. These features raised a number of diagnostic considerations, including: mature teratoma, hamartoma, rudimentary parasitic twin, lipomyelomeningocele and dorsal accessory limb.

Conclusions:

Based on review of the literature, the authors hypothesize that there is a pathogenetically related spectrum of skin-covered dorsal mass lesions, often associated with spinal dysraphism. These consist of a major lipomatous component and a variety of mature germ layer derivatives that can vary widely in their degree of anatomical organization from case to case.

An accessory limb with lipomyelomeningocele in a male

At 7 months, an infant born with a third limb attached to a lumbosacral mass with an associated lipomyelomeningocele underwent removal of the limb and spinal cord detethering. Depending on the complexity of the pathology and proximity of the limb to viscera, consultation with neurosurgical and surgical colleagues is recommended.

Parasitic conjoined twins: external, internal (fetuses in fetu and teratomas), and detached (acardiacs)

During the course of researching the embryologic etiology of conjoined twins, more than 1260 individual cases were collected from the literature and the reported abnormal anatomy tabulated and evaluated in the light of known embryology. It soon became apparent that the association of conjoined twins and their parasites with fetuses in fetu, acardiacs, and teratomas was more frequent than could be attributed to chance. These anomalous fetuses form a continuum, strongly suggesting that they are all variations of abnormal conjoined twinning, with the site of union and the extent of damage (or defect) of one embryo resulting in (1) an externally attached parasitic twin, (2) an enclosed fetus in fetu, (3) an internal teratoma, or (4) an acardiac connected via the placenta. Common patterns among them are a family history of twinning, the predominance of females, and the frequent presence of a twin or triplet accompanying the malformation. The several reports of chromosomal abnormality suggest that perhaps, at least on occasion, it is a genetically imperfect embryo that develops into a defective fetus. Of singular importance is the fact that rarely, if ever, is either a functional heart or a competent brain found in any of these abnormal fetuses, suggesting that the etiology of all of them is a primary cardiac malformation with secondary disruption in the development of the brain.

Imaging of an unusual case of parasitic twinning

Conjoined twins are rare in the literature and parasitic conjoined twins are rarer still. To our knowledge no cases of parasitic conjoined twins have previously been reported in the radiology literature. We present a case of parasitic conjoined twins in which radiographic findings played an important role in management.

Morphology of a six-legged goat with duplication of the intestinal, lower urinary, and genital tracts

BACKGROUND

An adult female goat with rare malformations, which consisted of duplication of the intestinal, lower urinary, and genital tracts as well a pair of parasitic appendages, is presented.

METHODS

A complete dissection was performed on a moribund female goat (Capra hircus).

RESULTS

The animal had a normal body with a parasitic attachment located within the pelvic region. This attachment was represented by an ovoid, trunk-like, adipose mass that lacked internal organs or vertebrae but that had two fairly well-developed limbs with the normal components of hind limbs. There was duplication involving the external and internal genitalia, the urethra, the urinary bladder, and portions of the small intestine as well as the large bowel, including the anal openings.

CONCLUSIONS

An autosite with a duplication involving the hindgut and paramesonephric anlages was identified. These features were compatible with life in utero and postutero and emanated from incomplete twinning (heteropagus twins). A review of the literature also suggests that heteropagus twins are a very rare abnormality in both domestic animals and humans.