Transcript FETUS IN FETU : A CASE REPORT

FETUS IN FETU : A CASE REPORT
 ABSTRACT ID NO : IRIA 1036
Overview
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Introduction
Clinical presentation
Imaging
Intra-operative findings
Histopathology
Discussion
References
Introduction
♣ Fetus in fetu is a rare congenital anomaly
♣ Due to unequal division of totipotent inner cell mass of
developing blastocyst.
♣ Result is inclusion of a small cell mass within a
maturing sister embryo.
♣ Thus a
vestigial remnant representing co-twin in a
diamniotic
monochorionic
pregnancy
gets
incorporated within body of otherwise normally
developed twin
♣ Most common site is retroperitoneum, however it
has been reported in other sites as well from
cranial cavity to the scrotal sac
♣ It is differentiated from teratoma by the presence
of vertebral organization with limb buds and organ
systems.
♣ Unlike teratomas, it is a benign condition.
Clinical
presentation
 2 ½ year old girl
 Asymptomatic Painless mass
in right hypochondrium
 7 x6 cm, firm , well defined ,
non-tender mass noted
which was extending to
epigastric, umbilical and
right iliac fossa.
 Family history of paternal
twinning was present.
Frontal projection
 Multiple dense radio-opacities in right upper
quadrant of abdomen resembling well formed limb
bones and spine
 Magnified view :–Thick arrowslimb bones
Thin arrowsspine;curved arrowspelvic bones;
Computed tomography
 Heterogenous well defined soft
tissue mass in right anterior
pararenal space in suprarenal
location.It showed multiple
bony densities within
resembling spine,limb
bones,ribs,pelvic bones.These
bony densities were surrounded
by soft tissue and fat.
Computed tomography
 Thick arrowslimb bones
 Arrowspine;Arrowheadribs
 Volume Rendered Image showing fetus in fetu
Intra-operative findings
♣ Right upper quadrant mass of 10 x12 cm covered
with sac pushing liver towards left and right
kidney anteriorly with stretched out right renal
vessels.
♣ Vascularity is from a direct branch of IVC
♣ On opening the sac ,50 ml vernix caseosa was
present
♣ Anencephalic head, spine, Upper & lower limb
buds with nails and partial differentiation of
digits were noted.
Retroperitoneal mass covered
with sac
Histopathology
 Gross examination
 Partially
developed
fetus
with
partial
differentiation of 4 limbs skull & spine with
palpable vertebrae,bones,scapula, ribs.
 Microscopy
 Microscopic sections showed mature derivatives of
ectoderm, mesoderm and endoderm.
 No immature component identified. There was no
evidence of somatic or germ cell malignancy.
 F/S/O Fetus in fetu
Specimen showing hair and
limb buds
Partial differentiation of
vertebrae
Discussion
 Incidence of Fetus in fetu is 1 in 500,000 live
births.
 Fetus in fetu occurs relatively equally in male and
female patients(1)
 It most likely represents a monozygotic diamniotic
twin that implants itself and grows within the
body of its normal karyotypically identical sibling.
 Presents as abdominal lump(70%)
 The mass is located in the retroperitoneum in
most cases,including our case, and is commonly
surrounded by encapsulated fluid (1,2)
 Fetus in fetu has been reported to occur in other
locations, such as within the cranium (3),within the
scrotum (4), and within the oral cavity (5)
 Most common presentation is a single parasitic fetus
(88%), however multiple fetuses ranging from 2 to 5
have also been reported.
 Reported fetal size between 4- 24 cm and fetal weight
varies between 1.2 kg to 1.8 kg
 Controversy exists as to whether a fetus in fetu is a
distinct entity or a highly organized teratoma.
 Willis(6) proposed that identification of vertebrae
on HPE or radiology differentiates both entities.
 Fetus in fetu occurs in upper retroperitoneum
while Teratoma occurs in the lower
retroperitonium, pelvis, ovary and sacrocoocygeal
region.
 Malignant tranformation is rare.
References
 1.Hoeffel CC, Nguyen KQ, Tran TT, Fornes P. Fetus in fetu: a case report
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and literature review. Pediatrics 2000; 105:1335–1344.
2.Chen CP, Chern SR, Liu FF, et al. Prenatal diagnosis, pathology,and
genetic study of fetus in fetu. Prenat Diagn 1997; 17:13–21.
3.Kimmel DL, Moyer EK, Peale AR, Winborne LW, Gotwalss JE. A
cerebral tumor containing five human fetuses: a case of fetus in fetu.
Anat Rec 1950; 106:141–165
4.Kakizoe T, Tahara M. Fetus in fetu located in the scrotal sac of a
newborn infant: a case report. J Urol 1972; 107:506–508.
5.Senyuz OF, Rizalar R, Celayir S, Oz F. Fetus in fetu or giant
epignathus protruding from the mouth. J Pediatr Surg 1992; 27:1493–
1495
6. Willis RA. The structure of teratomata. J Pathol Bacteriol 1935;40:1–
36.
Thank
you
4/5/2016