Biomed Imaging Interv J 2006; 2(3):e20
doi: 10.2349/biij.2.3.e20
© 2006 Biomedical Imaging and
Intervention Journal
Case Report
Benign teratoma of the liver: a rare cause of cholangitis
K Rahmat*,1, MBBS, FRCR, MRad,
A Vijayananthan1, MBBS, MRad,
BJJ Abdullah1, MBBS, FRCR,
SM Amin2, MBBS, FRCS
1 Department of Biomedical Imaging, Faculty of Medicine,
University of Malaya, Kuala Lumpur, Malaysia
2 Department of Surgery, Faculty of Medicine, University of Malaya,
Kuala Lumpur, Malaysia
ABSTRACT
Teratomas are neoplasms characterised by an abnormal growth
of tissues derived from the three germinal layers. The term ‘teratoma’ is
derived from the Greek root ‘teratos’, meaning monster. Germ cells develop in
the embryo and subsequently become the cells that make up the reproductive
system. During fetal development, these cells follow a midline path and descend
into the pelvis as ovarian cells or the scrotal sac as testicular cells. The
presence of germ cells in extragonadal sites is because of the failure of these
cells to migrate along the urogenital ridge. Therefore, teratomas occur in
order of decreasing frequency in the ovaries, testes, anterior mediastinum,
retroperitoneum, sacrococcygeal region and cranium.
Liver teratomas are very rare; of the 25 hepatic teratomas
described in the literature, only five have occurred in adults. The majority of
the cases were in female children below the age of three, mostly arising in the
right lobe of liver.
We report a case of an adult male with benign mature
teratoma arising in the left lobe of liver, compressing the common bile duct
and causing obstructive jaundice. © 2006 Biomedical Imaging and Intervention
Journal. All rights reserved.
CASE REPORT
A 46-year-old man was admitted for progressive jaundice and
pyrexia occurring arbitrarily for a month. He also complained of episodes of
chills and rigors, and showed significant weight loss. The patient was passing
pale coloured stools and had pruritus. He also had a history of vomiting
associated with upper abdominal pain. There was no history of bleeding
tendencies, and the patient claimed to be non-alcoholic. His previous medical
history was normal.
On clinical examination, he revealed jaundice with scratch
marks seen on the skin of the arms and abdomen. His urine was dark coloured,
and there was a palpable tender firm epigastric mass extending to the right
hypochondrium.
The blood examination was consistent with obstructive
jaundice: total bilirubin 99 mmol/L (3-17 mmol/L) conjugated bilirubin 93 mmol/L
(0-3 mmol/L), alanine transaminase 127 IU/L (30-65 IU/L), aspartate
transaminase 50 IU/L (15-37 IU/L), alkaline phosphatase 196 IU/L (50-136 IU/L)
and GGT 124 IU/L (15-85 IU/L). A full blood count showed a haemoglobin level of
127 g/L, white blood cell count of 11.7 x 109 and platelet count of
320 x 109 . Hepatitis serology was negative, and the diagnosis was
obstructive jaundice secondary to possible pancreatic malignancy.
An ultrasound examination revealed a heterogenous solid mass
measuring 5.0cm x 6.5cm x 8.0cm with echogenic areas in the epigastrium, medial
to the gallbladder. The left lobe of liver was atrophic, and the intra and
extra hepatic biliary ducts were of normal calibre.
A contrast enhanced computed tomography (CT) examination (Figures
1 and 2) revealed a heterogeneous mass in the anterior upper quadrant, located
medial to the left hepatic lobe, anterior to the main portal vein and the head
of pancreas. This mass consisted of dense calcification, fat and soft tissue,
and compressed the common bile duct (CBD). The CBD was dilated and the
lobulated lesion was clearly demarcated from the atrophic left lobe of liver
and the porta hepatis. This mass was diagnosed to be a teratoma of either
peritoneal or hepatic origin.
Magnetic Resonance Cholangiopancreaticography (MRCP) was
performed to further evaluate the biliary system and characterise the lesion.
The mass, seen in the CT examination, was identified as a mixture of fat and
soft tissue measuring 8.5cm x 6.3cm x 6.7cm. There was no communication between
this mass and the biliary tree (Figures 3 and 4). The distal CBD was compressed
by this mass.
Exploratory laparatomy was performed the same day and
revealed a fatty encapsulated tumour lying below segment IV of the liver
compressing the CBD. The hepatic artery was seen coursing through the mass, and
had to be ligated before it was successfully resected en mass with the tumour
and the atrophic left lobe of liver. The operating surgeons were of the opinion
that the mass could represent an angioliposarcoma, because of its gross
appearance.
The gallbladder was also removed. The rest of the liver,
mesenteric vessels, spleen and bowels were normal. Gross pathologic examination
showed the tumour mass attached externally to a piece of liver tissue, which
was resected. The cut section showed fatty tissue, cystic areas containing
sebaceous material and hair admixed with a firm fibrotic tissue. The resected
hepatic artery was thick and fibrotic with a short course draining into the tumour.
The histology showed a mixture of mature adipocytes, hyalinised
fibrous tissue, bony trabeculae and calcification. The attached liver showed
cholestasis. The final pathologic diagnosis was mature benign teratoma. An
ultrasound of the testes was performed and found to be normal. The patient was
discharged and is currently on follow up at the surgical clinic.
DISCUSSION
Teratomas are congenital neoplasms characterised by an
abnormal growth of a combination of tissues derived from ectodermal, mesodermal
and endodermal germ layers. This combination of tissues is unrelated to the
organs where the tumour originates [1]. These primordial germ cells are initially detectable in the yolk sac of the four week embryo, and their migratory route during embryogenesis from the yolk sac to the gonads may account for the midline location of most
extragonadal teratomas. They can be categorised as benign or malignant on the
basis of their histopathological features.
These tumours mostly occur in the ovaries or the
sacrococcygeal region in children. Less common anatomical locations include the
testes, mediastinum and central nervous system. There have been rare cases of
these tumours occurring in gastrointestinal tract, liver, nasal sinuses, cervix
and thyroid [2].
Teratomas of the liver are rare neoplasms accounting for
less than 1% of all teratomas. Even in paediatric patients where they are most
commonly seen, they account for less than 1% of all liver neoplasms. In adults,
benign teratomas do not directly affect the general condition of the patient;
compression of the surrounding structures causes symptoms of abdominal
distension, nausea and vomiting.
Occasionally acute abdominal pain can develop with malignant
neoplasms, which are thought to cause rapid degeneration [3]. Hepatic teratomas are usually well encapsulated lesions and are easily resectable from the surrounding hepatic parenchyma [1], as was discovered by our surgeon.
In our patient, although the histology did not demonstrate tumour
cells of hepatic origin, during the surgery, it was evident that the teratoma
originated from the left lobe of liver in view of its common peritoneal
attachments as well as capsular encasements. The CBD was compressed by the
large tumour, which explained the occurrence of jaundice. The hepatic artery
had to be ligated before it was resected en masse as it was encased
within the tumour. A left hepatectomy was subsequently performed.
As previously mentioned, a teratoma is histologically
composed of a variety of tissue elements. In our case, the histology revealed a
mass containing solid adipose tissue, bony trabeculae, hair, fibrillary neural
tissue and calcification.
Plain radiographs usually demonstrate a soft tissue mass
with lucent fat opacity and calcifications, either rim like or chunky. An
ultrasonography may demonstrate a hypoechoic (representing calcification or
fat) or anechoic (representing the cystic portion of this mass) component.
Calcification demonstrates posterior acoustic shadowing.
Bony tissue and calcification appear as high density foci on CT while fat is
readily identified as hypodense with a HU of -60 to -100, demonstrating a
density similar to subcutaneous fat. CT permits unequivocal identification of
fat as adipose tissue and the characterisation of fluid as sebum, serous or
complex. A component of a tumour that has both a CT attenuation value of fat
and a horizontal interface with another more dependent type of fluid, most
likely represents sebum [4].
In magnetic resonance imaging (MRI), calcification and bone
produce no signal. Solid adipose tissue is of high signal intensity on both T1
and T2-weighted images. Fluid components are typically hypointense on T1 and
hyperintense on T2-weighted images. The dermoid plug or Rokitansky protuberance
is described by Anderson and Kissane [5] as an outgrowth from the inner surface of a cyst, containing hair and other atypical tissues and is one of the MRI findings of teratoma.
MRCP was useful in this case to demonstrate the compression
of the CBD by the adjacent teratoma. Furthermore the delineation of the large
vessels and the relationship of surrounding structures, as seen on the MRI was
helpful in surgical planning, because all teratomas should be removed
completely if possible, regardless of its benignity or malignancy.
In conclusion, the case described here represents a rare
case of liver teratoma with interesting and characteristic CT and MRI
correlation.
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Received 12 October 2005; received
in revised form 8 February 2006; accepted 26 February 2006
Correspondence: Department of Biomedical Imaging,
Faculty of Medicine, University Malaya, 50603 Kuala Lumpur,
Malaysia. Tel: +603-79492069; Fax: +603-79581973; E-mail:
katt_xr2000@yahoo.com
(Kartini Rahmat).
Please cite as: Rahmat K, Vijayananthan A, Abdullah BJJ, Amin SM, Benign teratoma of the liver: a rare cause of cholangitis, Biomed Imaging Interv J 2006; 2(3):e20
<URL: http://www.biij.org/2006/3/e20/>
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