Retroperitoneum.
Retroperitoneal fibrosis
Background: The French urologist Albarran first
described retroperitoneal fibrosis (RPF) in 1905,
but with Ormond's publication in 1948,
the disease became an established clinical entity.
Ormond’s disease
In most patients (approx. 68%), no etiologic factor is found.
Therefore, the term idiopathic RFP is used. Recent evidence suggests that RPF is an
autoimmune response to an insoluble lipid called ceroid that has leaked through a
thinned arterial wall from atheromatous plaques.
Other implicated causes include drugs, abdominal aortic aneurysm, ureteric renal
injury, infection, retroperitoneal malignancy, postirradiation therapy, and
chemotherapy.
No genetic predominance is seen in malignant retroperitoneal fibrosis.
RPF can be diagnosed on the basis of the history and the
radiologic observations.
At times, the diagnosis is not established firmly until surgical
exploration.
The use of steroids in RPF remains controversial; however,
some authors believe that steroids can be used as an
adjuvant to surgical ureterolysis.
More recently, immunosuppressive drugs, such as
azathioprine, cyclophosphamide, and tamoxifen,
have been used to treat RPF.
RPF is relatively uncommon, with an
incidence of 1 case per 200,000 population.
The age range of patients is 7-85 years,
with predominance in patients aged 40-60 years.
Clinical Details: Most patients present with nonspecific symptoms of less
than 12-months' duration. Children may present with hip or gluteal pain.
In the early stage, signs and symptoms originate from the disease process;
in the advanced stage, clinical features represent the effects of obstructive
uropathy and renal failure.
The most common presentation is:
• pain (92%) occurring in the flank (42%), the back
(32%), the scrotum (8%), or the lower abdomen (28%).
Other presentations include:
fever,
weight loss (38%),
nausea and vomiting (32%),
malaise (18%),
polyuria (18%),
polydipsia (18%),
anorexia (15%),
nocturia (13%),
oliguria (10%),
urinary frequency (8%),
and hematuria (2%).
Hypertension is a common clinical feature.
The disease has been reported to manifest as constipation and large-bowel and duodenal
obstruction. Fibrotic processes can also cause compression of the great vessels, resulting
in thrombophlebitis and arterial insufficiency.
RPF has been documented to present as jaundice resulting from involvement of the
common bile duct and exophthalmos resulting from retro-orbital disease.
RPF can appear at a later stage as a complication of fibrosis. The patient may present
with renal failure resulting from ureteric involvement. Venous and lymphatic obstruction
may present as lower-limb edema. Claudication may result secondary to arterial
insufficiency. Invasion of the duodenum and colon and the common bile duct has been
documented as causing bowel obstruction and jaundice, respectively. Neurologic
presentation secondary to spinal epidural extension has been reported.
The diagnosis of RPF often is delayed because of its nonspecific presentation.
Laboratory findings:
• Anemia
• increased erythrocyte sedimentation rate (ESR).
• Elevated white cell counts and pyuria can occur.
Retroperitoneal fibrosis. Plain abdominal
radiograph of a patient with biopsy-proven
retroperitoneal fibrosis shows a calcified
mass in the retroperitoneum
(to the right of the mid lumbar spine).
Retroperitoneal fibrosis. Excretory
5-minute urographic image
demonstrates medial deviation of
the right ureter at the L3-L4
vertebral level, which is
suggestive of retroperitoneal
fibrosis. Note the delayed
excretion of the hydronephrotic
left kidney.
Retroperitoneal fibrosis. Excretory 15minute urographic image (same patient
as in Image 2 and obtained 1 year
later) shows progression in the severity
of hydronephrosis. Smooth tapering of
the medially deviated ureters is noted.
Retroperitoneal fibrosis. CT scan in a 62year-old man shows a soft-tissueattenuating mass encircling the abdominal
aorta. Note the extension of the soft-tissue
mass around the left kidney. A right-sided
nephrostomy and a left ureteric stent are
seen.
Retroperitoneal fibrosis. CT scan in a 62year-old man (same patient as in first
Image) shows a soft-tissue-attenuating
mass encircling the common iliac arteries.
Retroperitoneal fibrosis.
Aortic and common iliac arterial graft
in a patient with severe arterial
insufficiency secondary to
retroperitoneal fibrosis.
Note a nephrostomy catheter in the
right renal collecting system and the
fragmented left ureteric stent.
Plain radiographic findings in RPF are nonspecific, and most findings are related to the late
complications of fibrosis, such as bowel obstruction and pulmonary edema secondary to renal
failure.
Contrast-enhanced studies, such as barium follow-through and barium enema examinations, can
show the level of bowel obstruction. The diagnosis of RPF has often been suggested on the basis
of the excretory urographic findings due to extensive changes in the urinary tract.
Retrograde pyelography is used in patients with severely impaired renal function.
Aortography, venography, and lymphangiography help in assessing the level and extent of
occlusion; however, findings from these examinations can be normal in advanced disease.
Ultrasonography can be used as a noninvasive technique. Sonograms may or may not help in
identifying the retroperitoneal mass, but they can readily demonstrate the degree of obstruction to
the ureters and kidneys. Attempts have been made to differentiate benign RPF from malignant RPF
by using color Doppler imaging.
Computed tomography (CT) and magnetic resonance imaging (MRI) provide superior delineation
of the extent of the masses of RPF.
Isotope renography is useful in the serial assessment of renal function. Gallium scintigraphy may
demonstrate increased uptake, depending on the activity of inflammation. The use of 2-[fluorine
18]-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) in differentiating benign
from malignant RPF is promising.
Other Problems to be Considered:
RPF must be differentiated from other conditions that can cause ureteric
obstruction and renal failure, such as
retroperitoneal abscess,
infections,
inflammation,
pelvic surgery,
and radiation therapy.
Unusual causes that can cause ureteric obstruction include
barium granuloma after colon perforation,
use of sclerosing agents for treatment of inguinal hernia and
hemorrhoids, and methyl methacrylate cement used for joint
replacement.
Imaging appearances similar to those of RPF can be demonstrated by
abdominal aortic aneurysm;
tumors inducing desmoplastic response, such as lymphomas,
sarcomas, and pancreatic carcinomas;
and metastatic malignancies from the breast, lung, stomach, colon,
kidney, bladder, prostate, and cervix.
Other conditions that may simulate RPF include periaortic hematoma
and amyloidosis.
Intervention:
Biopsy can be performed under CT guidance to differentiate benign masses from malignant
retroperitoneal masses.
Drainage of the upper urinary tract can be performed as a temporary measure.
Percutaneous nephrostomy and the insertion of a double-J stent helps restore renal function and
allows time to improve fluid, electrolyte, and acid-base balance prior to surgery.
Treatment:
The use of steroids in RPF remains controversial; however, some authors believe that steroids can
be used as an adjuvant to surgical ureterolysis.
More recently, immunosuppressive drugs, such as azathioprine, cyclophosphamide, and tamoxifen,
have been used to treat RPF.
In drug-related RPF, cessation of the drug therapy can result in restitution of the urinary tract and
disappearance of the symptoms.
Retroperitoneal tumors
Primary tumors of the retroperitoneum
develop independently from cells
distinct from the major retroperitoneal
organs such as the:
pancreas,
kidney,
adrenal gland,
major blood vessels.
The cause is unclear.
Rarely, a history of therapeutic radiation usually more
than 10 years before onset.
The incidence of reported sarcomas after therapeutic radiation is low, ranging from
0.03 to 0.3 percent, with the most common type being malignant fibrous
histiocytoma.
Exposure to vinyl chloride, thorium dioxide, and other
agents is associated with sarcomas.
Several familial disorders such as Gardner's syndrome, familial
retinoblastoma, neurofibromatosis, and Li- Fraumani syndrome are associated with
benign and malignant soft tissue tumors.
Germ-line mutations of the p53 tumor suppressor gene on chromosome 17 is
present in some of these familial disorders. Retroperitoneal sarcomas are relatively
rare mesenchymal and neurogenic tumors often occurring in the fifth or sixth
decade of life.
Despite their rarity, they should be considered in the differential diagnosis of an
unknown abdominal mass.
The most common RP malignancies are:
sarcomas,
lymphomas,
extragonadal germ cell tumors,
and carcinomas
Approximately 6000 soft tissue sarcomas annually
(USA),
nearly 1000 of these occur in the retroperitoneum
Retroperitoneal tumors generally arise from mesodermal or
neuroectodermal tissues or remnants of the embryonal
urogenital apparatus.
Tumors may arise from:
•
•
•
•
•
•
•
fat,
aerolar tissue,
vascular or nervous tissue,
muscle,
fascia,
lymphatics,
nodal tissues.
Tumors of smooth muscle origin, germ cell tumors, teratomas,
and other complex lesions also may occur.
Lymphomas and retroperitoneal sarcomas
are the most common malignant lesions of the retroperitoneum
Define: margins, size, and histologic grade to obtain prognosis
The American Joint Commission on Cancer criteria distinguish
three grades and tumor sizes 5 cm and less or more than 5
cm to provide prognostic criteria, but other systems use only
two grades.
A low grade is assigned to myxoid and well- differentiated
liposarcoma and high grade to rhabdomyosarcoma, synovial
sarcoma, and alveolar soft part sarcoma
If metastasis occur, it typically spreads hematogenously to
liver and lung.
Lymph node metastases are rare ( < 5% )
Symptoms are produced by compression or obstruction
of adjacent tissues.
• an enlarging mass in the abdomen,
• a vague abdominal discomfort,
• a sense of fullness or heaviness.
Pain may become severe if compression of adjacent
nerves or nerve plexuses occur.
Gastrointestinal stromal cell tumors (leiomyosarcomas)
may result in nausea, vomiting, intestinal obstruction, and
gastrointestinal bleeding.
Occasionally, fever, weakness, weight loss, and
genitourinary symptoms can occur depending on the size
and location of the neoplasm.
Pelvic tumors give rise to urinary frequency or rarely
anuria. They also may compress pelvic veins resulting in
lower extremity swelling and varicosities.
Lab. studies :
serum a-fetoprotein
β -human chorionic gonadotropin
should be obtained to exclude
retroperitoneal germ cell tumors.
CT scan. Use of fast, helical CT scanners allows excellent definition of the extent of the mass, the
potential involvement of vital organs or major vascular structures with the primary tumor, and the
involvement of the liver, lungs, or peritoneal cavity with metastases.
MRI is an excellent diagnostic tool permitting sagittal and coronal views and providing a threedimensional image to define tumor extent and resectability.
Use of contrast enhancement with gallium may be helpful to improve specificity and sensitivity of
the examination. These studies can determine tumor size and whether the lesion is solid or cystic.
They also are useful for planning the operative approach using abdominal, flank, or
thoracoabdominal incisions.
Ultrasound, gastrointestinal barium studies, and angiography (aortography) are rarely indicated
except when gastrointestinal stromal tumors are suspected.
If lymphoma is suspected as the cause of a retroperitoneal mass, a CT- directed needle biopsy
often can be done. Fine-needle aspirates are used, but most pathologists require analysis of cells
and stroma for diagnostic accuracy, requiring a percutaneous needle biopsy.
The exact location of the retroperitoneal mass, its appearance, and the presence or absence of
adenopathy and lymphoma (B) symptoms of fever, weight loss, and night sweats dictate whether a
biopsy should be performed.
Preoperative tissue diagnosis is useful only if a lesion treated nonsurgically could be determined.
Despite their rarity, they should be
considered in the differential diagnosis
of an unknown abdominal mass.
EUS-guided FNA smears confirmed the diagnosis of malignancy and
showed clumps of atypical cells.
Patient diagnosed by transabdominal ultrasound with a large
retroperitoneal tumor in contact with the left liver lobe. EUS
allowed the visualization of the tumor from the stomach with
absent power Doppler signals inside.
EUS-guided FNA (fine needle biopsy) smears confirmed the
diagnosis of malignancy and showed clumps of atypical cells.
Laparoscopic ultrasound.
Laparoscopic ultrasound.
1: Liver
2: Delineated tumor at 3 cm. ( Leiomyoma )
Case report I
A 50-year old woman was admitted to our surgical department because of recurring, intermittent
pain in the right upper quadrant of two month duration. 6 days before admission her symptoms did
aggravate. On physical examination the patient showed abdominal distention. The liver was
enlarged and its edge was palpable 11 cm under the costal margin in the right midclavicular line.
Cardiopulmonary examinations was unremarkable. Her family and past histories were not
contributory. Laboratory tests and tumour markers were within the normal limits.
The chest radiograph showed elevation of the right hemidiaphragm.
Initial US scan showed liver enlargement and the right lobe was
nearly completely filled with tumor mass.
A CT scan revealed a a bulky mass 20x16x17 cm in the right lobe of
the liver, inhomogeneously enhancing in the late phase. CT cannot
rule out infiltrating the inferior vena cava from the diaphragm level
till the renal arteries. The spleen was enlarged, but without any
other changes. The right kidney was pushed down and enlarged
with signs of urine retention. The left kidney was normal.
The primary diagnosis: tumor of the right lobe of the liver.
Laparotomy was performed through Kocher’s incision.
Intraoperatively, a 24 cm tumor was found in the retroperitoneal
space probably arising from the right adrenal gland infiltrating
the right renal artery.
There were 4 metastases 2-3 cm in diameter one located in the
transverse colon mesentery and rest in the small bowel
mesentry.
The mass was excised with the right kidney, and metastases was also
excised.
The histopathological diagnosis showed that tumour cells were
positive for CD-68, S-100 and negative for wimentin, cytokeratin,
LCA, CD-34 and a diagnosis of dedifferentiated liposarcoma was
made.
The metastatic tumours had the same histological structure.
In the postoperative period the patient developed ileus due to
necrosis of the small intestine loop and was reoperated. The recovery
was complicated with the wound infection. The patient was
discharged after 35 days of hospitalization.
Case report II
A 36-year-old man presented with gradually increasing abdominal
discomfort. Physical examination suggested a mass in the pelvis.
Computed tomographs (CT) of the lower abdomen and pelvis with oral and intravenous
contrast demonstrate a 12 x 11 x 11 cm mass centered anterior to the sacral promontory
displacing the left psoas muscle posterolaterally and the bladder dome posteriorly and to
the right. The mass has well-defined margins without apparent invasion of surrounding
structures. Its attenuation is heterogeneous with predominantly muscle-density material,
but fatty components are also present. From its location within the pelvis and its relation
to adjacent retroperitoneal structures, the mass appears to be retroperitoneal in origin.
Differential Diagnosis
This mass is most likely liposarcoma.
Teratomas contain fat, but also calcification (not present here), and would most
likely have arisen from the testis in this patient.
No evidence from the images suggests testicular origin.
Other mesenchymal tumors (engulfing adjacent fat), such as malignant fibrous
histiocytoma, desmoid, and leiomyosarcoma, are less plausible.
Lymphoma should also be considered. If the mass were more intimately related
to the anterior bladder wall and if calcification were present, a urachal
adenocarcinoma could be considered.
Diagnosis
Well-differentiated liposarcoma
Retroperitoneal liposarcoma is among the most common primary
retroperitoneal tumors, along with malignant fibrous histiocytoma and
leiomyosarcoma.
It is slow-growing and has a propensity to displace rather than invade adjacent
structures.
Histiologic subtypes include well-differentiated, myxoid (the most common form)
and pleomorphic.
Liposarcoma is most often seen in the fifth to seventh decades and is more
common in men. The appearance of fat in a retroperitoneal tumor can aid in
diagnosis. Fat is invariably present in liposarcoma and notably absent in less
well-differentiated masses. Calcifications occasionally are visible. The overall 5year survival rate is about 30%.
Case report III
• A 41-year-old woman underwent ultrasonography at a
medical check up for chronic hepatitis.
A round hypoechoic mass was detected in the Spiegel lobe of
the liver.
Blood analysis showed almost normal liver function with
positive hepatitis-C virus antibody.
Carcinoembryonic antigen and alpha-fetoprotein were both
negative.
Dynamic CT, in the early phase, showed a well-defined and
enhanced tumor (2.7 cm in diameter), which compressed the
inferior vena cava (IVC), and was well enhanced in the late
phase
The tumor could not be
revealed by celiac and
superior mesenteric
angiography and no other
feeding artery directly from
the aorta was identified.
left hepatic angiographic CT, and found that
the tumor was not enhanced.
No neoplasm was found upon examination
of the gastrointesnal tract, ruling out the
possibility that the tumor was a metastatic
carcinoma in the liver. The patient
underwent laparotomy under a preoperative
diagnosis of primary hepatic tumor with faint
neovascularity, possibly a scirrhous-type
hepatocellular carcinoma or a
cholangiocellular carcinoma.
At surgery, the tumor was found to be 3 cm in
diameter and located between the left caudate
lobe and the IVC, and was diagnosed as being
of a retroperitoneal origin. It was well
encapsulated, round with a smooth surface,
and elastic or stony hard.
It was separated from the liver and IVC without
difficulty after the dissection of two nerve-like
strings from the retroperitoneum attached to
the tumor.
The resected specimen demonstrated a hard and well-demarcated tumor without a
capsule, which was 2.8 * 2.2 cm in size and pale yellow with a heterogeneous
consistency at the cut surface in the gross section. Histological examination revealed
that the tumor was composed of densely packed spindle cells with oval nuclei arranged
in wide bands. The nuclei did not show palisading, and were not uniform in size, but
there was no mitosis. The tumor was stained positively for S-100 and vimentin, and
negatively for actin and desmin. Therefore, this tumor was finally diagnosed as a benign
retroperitoneal schwannoma. Liver biopsy showed mild active chronic hepatitis.
Schwannoma, a relatively rare retroperitoneal tumor,
has a reported incidence of only 0.5-1.2%, which
may make an accurate preoperative diagnosis
difficult
In the present case, plain CT first demonstrated
that the mass seemed to be located in the Spiegel
lobe of the liver. There was a hypodense band
between the tumor and lateral segment of the
liver, but not between the tumor and the paracaval
portion of the liver. We therefore thought the tumor
arose from the Spiegel lobe of the liver. Dynamic
CT then revealed that it was relatively
hypovascular, suggesting a hypovascular primary
liver tumor such as a scirrhous-type hepatocellular
carcinoma or combined hepatocellular carcinoma
and cholangiocellular carcinoma.