Dr.B.Vinod Dept.of General surgery Hyderabad,Telangana

1. RETROPERITONEAL
TUMORS
By:Dr.B.Vinod
Dept. of General surgery,
Gandhi medical college and hospital,
Hyderabad, Telangana.
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2. • Introduction
• Risk factors
• Clinical features
• Classification
• Investigation
• Management
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3. Introduction
• Primary retroperitoneal tumors (RPTs) refer to a group of rare
neoplasms arising in the retroperitoneum and pelvis
• Tendency for extensive growth before becoming clinically evident.
• Most cases tumors do not originate in a specific organ but rather
grow from connective tissues normally present in the
retroperitoneum and pelvis.
• RPTs represent a heterogeneous group of neoplasms comprising a
majority of malignant mesenchymal tumors and a minority of benign
lesions.
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4. • Incidence is approximately 2.7 cases /10 persons/ pear.
• Most of then are malignant & accounts for 0.1 to 0.2 % of all
malignancies in body.
• Sarcoms are second most common tumor of retroperitoneum & first
most primary retroperitoneal malignancy.
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5. • As a group RPTs represent a combination of sarcomas and other benign and
malignant lesions
• Liposarcoma
Leiomyosarcoma account for 80% of all retroperitoneal
Malignant fibrous histiocytoma sarcomas
• Benign mesenchymal tumors almost never transform into malignant
counterparts.
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6. Risk Factors
• Radiation exposure
• Genetic causes
• Carcinogen
• Immunodeficiency
• Viral infections
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7. Varying presentations.
• Asymptomatic:Diagnosis is accidental
• Symptomatic:Late presentation as abdominal lump
because tumor grows slowly and painless
and displaces adjacent organs.
• Constitutional symptoms
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8. •Due to compression on adjacent organs:
i) Back Pain- Severe back pain often following pressure by
• tumor mass over muscles, facet joint and vertebral column.
• Radicular Pain- Radiating type of pain along the nerve root due to its
compression.
ii) Obstruction of Viscera and Tubular Organs – usually of duodenum , colon ,
ureter , pancreas, kidney resulting in
• Nausea and Vomiting-
• Colicky Pain
• Constipation/ obstipation
• Urinary Retention
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9. iii) Compression of Aorta
• Hypertension-
• Renal Insufficiency-
• Mesenteric Ischemia-
• Intermittent Claudication
iv) Compression of Vena Cava
• Edema of Feet
• Low Blood Pressure
v)Nerve Lesions
• Tingling and Numbness in Lower limbs
• Weakness of the Lower
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10. On examination.
• No clinical findings unless the swelling is very large
• Consistency:Firm to hard mass
• Surface :Smooth , but in lymphoma it is nodular
• Borders: can not be traced properly because of deep position of the
swellings
• Not moving with respiration.
• Non mobile.
• Non tender
• Does not fall forward
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11. Classification of Primary Mesenchymal Tumors
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12. 12

13. Secondaries(Metastatic).
• Prostate
• Lung(SCC)
• SCC of cervix, vagina
• Pancreas.
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14. Benign tumors
• Benign RPTs are much less common than retroperitoneal sarcomas.
The more frequent of these are
Lipoma,
Myelolipoma,
Schwannoma,
Extra-adrenal pheochromocytoma,
Paraganglioma,and cystadenoma.
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15. LIPOMA
• Although subcutaneous lipoma is the most common benign
mesenchymal tumor, benign retro peritoneal lipoma is very rare.
• These are relatively small tumors, and when larger than 6 cm in
diameter they are considered malignant
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16. MRI imaging.
1
2
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17. Schwannoma.
• Benign tumor that arises from the perineural sheath
of Schwann cell.
• 6% of retroperitoneal neoplasms
• Common in females (2:1)
• Usually asymptomatic.
• CT, small schwannomas are round, well defined,
and homogeneous,
but large schwannomas may be
heterogeneous in appearance.
• Calcification(23%)
• Cystic degenerations (66%).
• Risk of malignancy 5% 17

18. 18

19. Angiomyolipoma
• Most common in females,20-35 yrs age
• Associated with tuberous sclerosis.
• CT and MR imaging shows small homogenous lesions and large
tumors are heterogenous containing fat cells and blood vessels.
• Presence of enlarged vessels differentiates from liposarcoma.
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20. MALIGNANT TUMOR.
Other retroperitoneal masses need to be differentiated from
retroperitoneal sarcomas which includes:
Lymphomas
Retroperitoneal fibrosis
Germ cell tumors
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21. Liposarcoma
• Liposarcoma is by far the most common type of retroperitoneal
sarcoma. Several classifications of these have been proposed.
• Enzinger and Winslow (1962) proposed five categories:
(1) myxoid,
(2) well differentiated,
(3) round cell,
(4) de-differentiated,
(5) pleomorphic.
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22. • CT images hypoattenuating lesion on because of its fat content.
• • Calcification is seen in 30% of cases
• The overall prognosis for patients with retroperitoneal tumors is worse
than that for patients with extremity sarcomas.
• Well-differentiated liposarcoma undergoes histologic dedifferentiation
and becomes more aggressive and metastatic and then carries a worse
prognosis.
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23. Myxoid
• Composed of primitive lipoblasts that do not have the typical fat-
laden cytoplasm but rather resemble primitive mesenchymal cells.
Abundant capillary network and myxoid matrix are other typical
components.
• Balanced translocation of chromosomes 12 and 16 t(12:16).
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24. Well-differentiated liposarcoma
• The histologic appearance closely resembles that of a benign lipoma,
and the distinction between the two by imaging and even under the
microscope is a challenge.
• In fact, many well-differentiated liposarcomas are misdiagnosed as
deeply seated lipomas.
• Ring chromosome 12 is typical of well-differentiated liposarcomas
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25. Round cell liposarcoma
• composed of small round cells uniform in size and closely packed
together. There is no specific pattern of cellular arrangement and
intracellular lipid content is scarce.
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26. De-differentiated liposarcoma
• characterized by the coexistence of well-differentiated and poorly
differentiated areas within the same tumor.
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27. Pleomorphic liposarcoma.
• Features include a disorderly growth pattern with cellular
pleomorphism, giant cells,and anaplastic pyknotic nuclei.
• Because this anaplastic tumor resembles other undifferentiated
sarcomas, some lipoblastic presence must be documented to confirm
this diagnosis.
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28. Leiomyosarcomas.
• Second most common (28%).
• Can grow to a large size >10 cm before compromising adjacent organs and
precipitating clinical symptoms such as venous thrombosis.
• M/C in females in 5 to 7 decades.
• Histology cells arranged in wavy sheets with cigar shaped nuclei
• It can be extravascular(62%),intravascular(5%),or
• combination(33%). of extra and intrvascular.
• At CT ,small tumors may be homogeneously solid,
but large tumors have
extensive areas of necrosis and occasional hemorrhage
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29. Axial MR imaging HPE
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30. Malignant fibrous histiocytoma
• Third most common(19%).
• Males(3:1)
• 5th to 6th decade
• CT and MR imaging appearances are nonspecific ,and present as
heterogenous mass wit areas of necrosis and hemorrhage
• Calcification seen in 10% of cases
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31. Rhabdomyosarcoma
• Most common pathology in paediatric age group.
• Has bimodal presentation.
• Eosinophilic granular cytoplasm either round or elongated
cells(tadpole).
• CT or MR imaging shows areas of calcification and areas of necrosis
with hemorrhages
• Metastasis occurs in 10 to 20 % cases
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32. Primary Extragonadal Germ cell tumors.
• Can be seminomous and on-seminomatous tumors.
• Retroperitoneum is second most common site for metastasis of
extragonadal germ cell tumors after mediastinium.
• Swellinng often seen in or near midline ,especially between T6 &S2
vertebrae
• Non seminomatous are present as
heterogenous mass with areas of necrosis and
hemorrhages.
The diagnosis of germ cell tumor can be established
easily by finding a testicular mass and
elevated relevant serum markers. 32

33. Teratoma.
• Germ cell tumor
• Less than 10% of teratomas
are found in the retroperitoneum.
• The third most common tumor in the retroperitoneum in children, after
neuroblastoma and Wilms tumor
• More common in females, with a bimodal age distribution (<6
months and early adulthood).
• Mature teratoma (dermoid cyst) contains well-differentiated tissues from
at least two germ cell layers.
• Mature teratomas are predominantly cystic.
• Calcification (toothlike or well defined) and fat can be seen in 56% and
93% of cases, respectively 33

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35. Lymphoma
• Most common retroperitoneal malignancy, accounting for 33%.
• Seen in the 40–70-year age group
• Frequently manifests with extranodal disease in the liver,spleen, or
bowel, often at an advanced stage.
• History of fever , myalgia , night sweats , weight loss
• Paraaortic lymph nodes are involved in 25% of the patients with
Hodgkin lymphoma and 55% of the patients with non-Hodgkin
lymphoma.
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36. • At CT, lymphoma is seen as a well-defined homogeneous mass.
• The aorta and IVC can be anteriorly displaced, producing the
“floating aorta” sign.
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37. Retroperitoneal and pelvic sarcomas
are classified as deep tumors
• Superficial tumor is located
exclusively above the superficial
fascia without invasion of the
fascia;
• Deep tumor is located exclusively
beneath the superficial fascia,
superficial to the fascia with
invasion of or through the fascia,
or both superficial yet beneath the
fascia
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38. STAGING OF RETROPERITONEAL SARCOMAS(TNM)
• T0 - No demonstrable tumor
• T1- Tumor measuring <5 cm in maximal diameter
T1a- superficial tumor
T1b- Deep tumor
• T2 - Tumor measuring =>5 cm in maximal diameter
T2a- superficial tumor
T2b- Deep tumor
• T3 - Evidence of macroscopic invasion of nearby structures by the
tumor
• N0 - No histologic evidence of regional lymph node involvement
• N1 - Histologically proved regional lymph node involvement
• M0 - No distant metastasis
• M1- Distant metastasis present
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39. Grading
• Gx: Cannot be assessed
• G1:Grade 1
• G2:Grade 2
• G3:Grade 3
• AJCC incorporates a three tired grading
system determined by
Mitotic activity(1-3)
Differentiation(1-3)
Necrosis(0-2)
Above 3 parameters are summed to grade
• Grade 1 2 or 3
• Grade 2 4 or 5
• Grade 3 6 or 6
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40. 40

41. Based on the extent of surgical resection of the
primary tumor(R)
• R0 - Tumor was entirely resected with no residual tumor and
negative surgical margins
• R1 - Microscopic residual tumor positive surgical margins
• R2 - Macroscopic residual tumor
• R3- Tumor spillage and dissemination during resection
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42. Investigations.
.Usg abdomen &pelvis : nature of mass(solid/cystic) and relation to the
adjacent structures.
.CT /MRI abdomen and pelvis.
.CT/USG guided core biopsy
.FNAC has got limited role as the representative
tissue may not be obtained .
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43. Routine blood investigations:
.Hemoglobin: anemia
.Blood and serum creatinine- raised on compression of kidney and
ureter
.Liver function test
. Effect of paraneoplastic syndrome
Hypoglycemia:- due to increased insulin like hormone
Catecholamines:- paraganglioma
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44. .Plane X ray abdomen:- signs of intestinal obstruction, obliterated
psoas shadow, calcification of tumor mass
.CT scan of chest.
lung metastasis
.Chest X ray PA view
.IVU :- Can show obstruction and displacement of
kidney and ureter, distortion of renal pelvis and bladder
compression.
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45. Indications of preoperative biopsy.
• Lymphomas
• Metastasis from a preexisting cancer is suspected.
• Patients with a suspected sarcoma in whom metastatic disease is
noted on imaging and a biopsy may guide subsequent systemic
therapy.
• A surgically resectable retroperitoneal/intra-abdominal sarcoma for
diagnosis and grading
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46. Management of primary localized RPS
• Surgery
• Radiation
• Chemotherapy
• Combined chemo-radiotherapy.
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47. Surgery
• En bloc resection with complete clearance of margin is standard
treatment for sarcomas .
• 40 to 60% are amenable to complete surgical resection.
• Nephrectomy (42%) followed by colectomy (30%) resection of intestine
are most common adjunctive surgery .
• Positive surgical margins are associated with high local
recurrence.(50% in 5 YRS ).
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48. • Approach : Open/Lap/Robotics
• Access : Inrtaperitoneal/ Retroperitoneal
• open intraperitoneal is most favoured
• Robotics approach has shown to decrease morbidity and mortality in
retroperitoneal tumor of size less than 3 cm.
• Incision : midline, rooftop (cheveron) , thoracoabdominal, Subcoastal.
• Cattell braasch maneuver approach to exposure of
retroperitoneal structures from Right-sided.
• Mattox maneuver to expose
retroperitoneum from left side
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49. Contraindications of surgery :
• Tumor invading major vascular structure
• Multiple Distant metastasis
• Gross peritoneal invasion / peritoneal disease
• Patient not fit for major surgery.
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50. Radiotherapy
NCCN .
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52. Chemotherapy
• Indications:-
Neoadjuvant(stage 3)
Unresectable tumor ( Palliative )
Distant metastasis
• Treatment regimens :
AIM :-Adriyamycin(20-25mg/m2 IV push on days 1-3) ,
Ifosfamide(2000-3000mg/m2 IV push bolus for 3 hrs on days 1-3 ,
Mesna(225mg/m2 IV over 1hr before Ifosfamide and 4 to 8 hrs
after ifosfamide)
Repeat every 3 – 4 weeks.
MAID:-Mesna , Iphosphamide, Adriyamycin, Dacarbazine(300mg/m2/day IV
infusion on days 1-3)
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53. Combined chemo-radiation.
• Doxorubicin dose: 20mg/m2/week for 4-5 weeks infusion.
• Radiation:- 18 to 50.4 Gy total radiation followed by 15 Gy IORT at
bed of resected tumour.
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54. Overveiw of management of
Retoperitoneal sarcoma.
• Stage I –surgery
• Stage II -pre-op radiation + surgery + post op radiation
• Stage III -Neoadjuvant chemo-radiotherapy +Surgery
• Stage IV –Palliative CTRT.
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55. Key Facts :
• Lymphoma is most common retroperitoneal tumor
• Liposarcoma is most common primary retroperitoneal tuomr
• Retroperitoneal sarcoma has got worse prognosis among all soft
tissue tumor
• Liver followed by peritoneum is most common site of distant
metasatsisof retroperitoneal tumor .
• FNAC has got no role is retroperitoneal sarcoma .
• CECT is investigation of choice for the retroperitoneal lesion.
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