Surgical Anatomy of Large Retroperitoneal Teratomas in Infants ...

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Surgical Anatomy of Large Retroperitoneal Teratomas
in Infants: Report of Two Cases
Ralf-Bodo Tröbs1, Christian Geyer2, Wolfgang Hirsch3 and Andrea Tannapfel4
1Department of Pediatric Surgery, Marienhospital Herne, Ruhr-University of Bochum, Widumer
Str. 8, D-44627 Herne, Germany. 2Department of Pediatric Surgery, 3Division of Pediatric Radiology,
University of Leipzig Medical Center, Liebigstr. 20, D-04103 Leipzig, Germany. 4Institute of Pathology,
BG Clinic Bergmannsheil, Ruhr-University of Bochum, Bürkle-de-la-Camp-Platz 1, D-44789
Bochum, Germany.
Abstract: We report on two infants of 11 and 12 months of age, respectively, with large solid-cystic retroperitoneal tumors.
Complete resection was achieved, and both children are doing well over a follow-up of more than 17 months. The presented
paper focuses on surgical anatomy of this very rare type of tumor. Teratomas were located mainly within the upper abdom-
inal cavity, and both tumors displaced the pancreas in an anterior position. The following anatomical features were observed
(1) displacement of surrounding organs, (2) deformation and elongation of large retroperitoneal vessels, (3) fi brous
incorporation of large vessels by the tumor pseudocapsule, (4) wrapping of anterior aortic branches by lobes and fi ngers of
the tumor.
Keywords: teratoma, retroperitoneal, retropancreatic, germ cells, anatomy
Teratoma is an embryonic neoplasm derived from totipotential cells that contain tissue from at least
two or more often three germ layers in variable proportions (Rowe et al. 1995; Gatcombe et al. 2004;
Laberge et al. 2005; Harms et al. 2006). It may contain mature and immature tissue components as well
as malignant elements. Retroperitoneal teratoma is very rare, and it occurs in only 3%–5% of teratomas
at all. Despite the availability of advanced imaging techniques the pediatric surgeon should have in
mind the expected anatomy of this type of tumor (Brasch et al. 1978). In a pioneer study by Hansmann
and Budd (1932) retroperitoneal teratomas together with other types of tumors were described as
“unattached retroperitoneal tumors” (Hansmann and Budd, 1932; Luo et al. 2005). The aim of our study
was to detailed information about the growth pattern and surgical anatomy of this type of neoplasm.
Furthermore, anatomical relationship to the pancreas was pointed out.
Case Reports
Case one
The twelve-month-old girl was referred to our hospital with a large abdominal protrusion. There was
neither any appetite loss nor vomiting. On physical examination a mass of 20 cm in diameter was
palpable within the whole upper abdomen. Serum AFP level (22 ng/ml) was at the upper border of the
age related confi dence interval. Ultrasound confi rmed the presence of a large heterogeneous abdominal
mass. Magnet Resonance Imaging (MRI) revealed a fat containing, solid and cystic retroperitoneal
tumor with broad contact to the large vessels (Fig. 1). Furthermore, spleen and pancreas were displaced
in an anterior position (Fig. 2). Chest CT excluded any pulmonary fi liations.
At surgery the bulky tumor occupied the whole retroperitoneal space of the upper and middle
abdomen. The maximum of the tumor was found in the right suprarenal region and protruded through
the foramen of Winslow. The pancreas was fl attened and stretched over the cranial portion of the
tumor. Tab. 1 outlines the anatomical relationships and landmarks. The tumor was resected totally.
Correspondence: Ralf-Bodo Tröbs, M.D., Professor of Pediatric Surgery, Department of Pediatric Surgery,
Marienhospital Herne, Ruhr-University of Bochum, Widumer Str. 8, D-44627 Herne, Germany.
Tel: +49 (0)2323 499 2451; Email: [email protected]
Copyright in this article, its metadata, and any supplementary data is held by its author or authors. It is published under the
Creative Commons Attribution By licence. For further information go to:

Clinical Medicine: Case Reports 2008:1 107–111

Tröbs et al
(extended and displaced)
portal vein
inf. mesent. vein
sup. mesent. vein
sup. mesent. artery
inf. caval vein
inf. mesent. artery
Figure 1. Solid—cystic teratoma containing different types of tissue
like fat, albuminous liquid and other solid parts (MRI, T1-gradient
echo sequence, coronal).
Figure 3. Anatomy of case one.*
*Many thanks to Doctor K. Welt for his drawing.
A schematic drawing of the topographic anatomy
is given in Figure 3. Pathological fi ndings: The
cut surface the was characterized by yellowish within normal limits. The girl had suffi cient gain
parenchyma, skin-like tissue, and a mature bone of weight. Repeated ultrasound controls and
with marrow. Microscopic investigation of the estimations of serum AFP excluded tumor relapse.
15 × 10 × 10 cm measuring tumor revealed the The girl is doing well and free of disease for
presence of mature derivates from all three germ 16 months postoperatively.
layers, for example fatty tissue, epidermis, periph-
eral nerve, cartilage, teeths, intestinal mucosa,
and intestine (Grade 0). The TNM tumor stage Case two
was T2b N0 M0.
The eleven-month-old Vietnamese boy was
After surgery the girl recovered within a couple admitted in our department with a large bulky
of days. Repeated controls of serum AFP stayed tumor of the abdomen. Previous clinical history
was unremarkable. AFP was normal (15 ng/ml).
The boy had bilaterally descended testes. Ultraso-
nography showed a large cystic-solid tumor located
within the upper abdomen (Fig. 4). Abdominal MRI
confi rmed a large mass with fatty components and
broad contact to the large retroperitoneal vessels
behind the mass. The mass displaced the left kidney
in a more lateral position, whereas the upper part
of the tumor extended to the retropancreatic space
and elevated pancreas and stomach. The top of the
mass protruded caudally to the transverse colon,
and it occupied nearly the whole upper and middle
fl oor of abdominal cavity. The tumor was com-
pletely excised en bloc. Pathological fi ndings: The
excised tumor measured 12 × 11 × 6 cm and the
cut surface mainly showed a cystic pattern.
Microscopic investigation revealed the presence of
mature derivates of all three germ layers (grade 0). The
TNM tumor stage was T2b N0 M0.
Figure 2. The same tumor as in Figure 1 in a transversal section.
Postoperatively the boy recovered quickly.
Pancreas and splenic vein are displaced towards ventral. (MRI, T1,
Repeated ultrasound investigations and serum AFP
Clinical Medicine: Case Report 2008:1

Retroperitoneal teratomas
described occasionally in previous papers (Lack
et al. 1985). For differential diagnosis mature
teratoma of pancreas and the adrenal gland has
been reported (Khong et al. 2002; Yu et al. 2003).
However, there were clear surgical plains between
the pancreas and the tumor. Furthermore, adrenal
tissue was not found in any of both tumors
described in this paper.
The retropancreatic extension of teratoma can
be explained by the germ cell theory. During early
embryonic development totipotential germ cells
migrate from their normal origin in the yolk sac
along the posterior mesentery of the hindgut to
the gonadal ridge and then to the gonad. Incom-
plete or erroneous embryonic germ cell migration
might occur and can be the origin of the teratoma
(Gatcombe et al. 2004; Laberge et al. 2005). This
process is accompanied by a clockwise rotation
of the foregut including the common bile duct and
ventral pancreas and resulting in fusion of the
ventral and dorsal pancreatic primordia in front
of the germ cells (Collins, 2002).Imaging studies
of mature retroperitoneal teratomas have reported
Figure 4. Zystic-solid teratoma in the left abdomen (case 2; MRI, T1,
heterogeneity of the mass. Solid-cystic teratomas
are complex neoplasms containing well circum-
scribed fl uid components, fatty regions (adipose
tissue and sebum in the form of a fat-fl uid-level),
measurements revealed normal results. The boy is and calcifi cations (Figs.1 and 2) (Gatcombe et al.
doing well over a follow-up of 17 months.
2004). Mature teratomas are described as well
circumscribed masses, showing no evidence of
invasion, and seem to affect adjacent organs
simply by virtue of their bulk (Davidson et al.
Retroperitoneal teratoma is the third most common 1989). In addition, retropancreatic localization of
retroperitoneal tumor in the pediatric population the teratoma, as it was found by imaging and
after neuroblastoma and Wilms’ tumor (Gatcombe confi rmed during operation in our two cases,
et al. 2004). Irrespective of the presence of seems to be a characteristic feature.
immature or malignant components complete
The main step of therapy for retroperitoneal
surgical resection is curative in the majority of teratoma is complete surgical resection and the
cases (Tapper and Lack, 1983; Lack et al. 1985; prognosis for children with retroperitoneal teratoma
Billmire and Grosfeld, 1986; Marina et al. depends primarily upon the adequacy of surgical
1999; Costero-Barrios and Lopez-Briano, 2003; resection (Tapper and Lack, 1983; Billmire and
Gatcombe et al. 2004; Luo et al. 2005). Previous Grosfeld 1986; Marina et al. 1999; Gatcombe et al.
studies have reported variably an anatomic 2004; Laberge et al. 2005; Luo et al. 2005). In
predilection for the left side, for the midline, and addition, successful laparoscopic removal was
for a suprarenal location (Gatcombe et al. 2004). reported (Gatcombe et al. 2004). Tapper and Lack
In our cases teratomas seemed to originate from (1983) described an advanced histological grade
the left, respectively right suprarenal region. As a correlates with larger tumor size and, hence,
consequence, the pancreas was found in front of unresectability (Tapper and Lack, 1983). Incom-
the teratoma of both cases. Retropancreatic plete resection predisposes to tumor relapse.
extension is a well known feature of adrenal Furthermore, the presence of small areas of
neuroblastoma and left sided nephroblastoma malignant cells, most commonly microfoci of yolk
(Kiely, 2005). In concern with teratoma it has been sac tumor within the teratoma may result in a high
Clinical Medicine: Case Report 2008:1

Tröbs et al
risk of recurrence (Gobel et al. 1997; Laberge et al. arteriography has been performed on fi ve cases
2005; Harms et al. 2006). Recurrence and late of benign retroperitoneal teratomas. This
malignant transformation of retroperitoneal tera-
investigation demonstrated a more avascular
tomas have been observed and require careful nature of these tumors (Brasch et al. 1978;
long-term follow-up with ultrasonography and Bruneton et al. 1980). Furthermore displacement
serum AFP measurements for all patients.
of the “digestive arteries” was described. How-
In order to prevent tumor spillage and to ever, at surgery large and essential vessels may
accomplish complete removal adequate exposure be partially or near completely surrounded by
of the tumor is essential. Surgery may be time lobes, and fi ngers of the teratoma. As observed
consuming and requires exact proceeding in both cases renal arteries and veins were
between tissue planes. Table 1 summarizes the stretched and depressed. In particular isolation
complex anatomical relationships of large retro-
of the large veins (superior mesenteric, portal,
peritoneal teratomas. The aim of surgery is to cava inferior, renal) requires careful isolation of
remove all tumor tissue. As well known from the pseudocapsule, the use of loops and stepwise
other retroperitoneal tumors identifi cation and identifi cation and dissection of many small and
clearing of large vessels are the most important short veins originating from the teratoma and
steps of surgery (Kiely, 2005).The surgeon draining in the large retroperitoneal veins.
should keep in mind that the large aortic branches Further on, vascular branches from the aorta and
as well as the venous roots of cava vein and the essential visceral and lumbar arteries have to be
portal vein have to be identifi ed and preserved. isolated and preserved (Brasch et al. 1978).
Furthermore, different rare anomalies and
malformations of the inferior vena and its
branches may occur and if unrecognized can lead Conclusion
to life-threatening complications (Mathews et al. Despite the description of retroperitoneal teratoma
1999). However, there is only a little information as an “unattached retroperitoneal tumor” anatomical
about vascular anatomy of retroperitoneal relationships of high complexity have to been taken
teratomas. In one historical study abdominal into account (Fig. 3) if surgery is performed.
Table 1. Topography and involvement of important anatomical structures.
Case 1
Case 2
Suspected origin
Right upper retroperitoneum
Left upper retroperitoneum
Foramen epiploicum
Caudally to transverse colon
In front
Cranially, in front
Not identifi ed
Cranially, in front
Transverse colon
Caudally to maximum
Cranially to maximum
Displaced to the right
Displaced to the right
Abdominal aorta
Behind, adherent
Behind, adherent
Inferior cava vein
Elongated, compressed,
Behind, adherent
and displaced to the right
Superior mesenteric vein
Not involved
Celiac trunk
Surrounded by tumor
Not involved
Superior mesenteric artery
Inferior mesenteric artery
Not involved
Renal vessels
Behind, adherent;
Behind, adherent;
left site elongated
left site elongated
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