DR. MD. SHALEH MAHMUDRESIDENT,UROLOGYPHASE- A, Y- 2BSMMU

RETROPERITONEAL MASS : ETIOLOGY & EVALUATION

Retroperitoneal anatomy Etiology Clinical features Investigations Common retroperitoneal masses

CONTENTS

RETROPERITONEAL ANATOMY

Retroperitoneum Boundary

Anteriorly : posterior parietal peritoneum

Posteriorly : Vetebral column, iliopsoas , quadratus lumborum muscle and tendinous part of transverse abdominis

Superiorly : Diaphragm

Inferiorly : Levator Ani and Pelvic Diaphragm

It is divided into three spaces by the perirenal fascia i.e. fascia of Gerota

The Three spaces are:

Anterior pararenal space Colon, Pancreas, Duodenum

Perirenal space Kidneys, Adrenal glands, Upper portion of ureters

Posterior pararenal space Fat , connective tissue, nerves

SPACES & CONTENTS

CAUSES OF RETROPERITONEAL SWELLING

Solid Neoplastic Retroperitoneal mass

Solid tumor from other sites: Lymphoma Metastatic germ cell

tumor Renal & Adrenal

Neoplasm Pancreatic Neoplasm Colonic Neoplasm

Cystic Neoplastic Retroperitoneal mass

Neurilemoma

Non- Neoplastic Retroperitoneal mass

Solid Cystic Retroperitoneal fibrosis ( ORMOND’S Disease)

Hematoma

Urinoma

Psoas Abscess

Pseudocyst

Others : Abdominal aorta aneurysm

CLINICAL PRESENTATION

Presentation Asymptomatic: diagnosis is

accidental or Incidental.

most common presentation is huge abdominal lump with compressive symptoms

presentation is usually late : because

i) tumors are slow growing & painless: pain occurs in benign pathologies like Hemangioma, Schwannoma, fibroma, hematoma etc.

ii) tumors displaces the adjacent structures. Infiltration occurs in late stages.

Due to retroperitoneal mass :1) No clinical findings unless the swelling is very large on

examination:

Consistency : Firm to hard mass , surface : Usually Smooth , but in lymphoma it is nodular , Margins : Ill defined because of deep position , Movement : Not moving with respiration , Mobility : Non mobile, Tenderness : Usually non tender, Pulsatility : sometime pulsatile, Does not fall forward (confirmed by knee-elbow position).

2) Dull aching abdominal pain or Flank pain if RCC

SYMPTOMS AND SIGNS OF RETROPERITONEAL MASS

Due to compression on adjacent organs :

i) Back Pain - Severe back pain by tumor mass, hematoma and abscess 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 etc.

Nausea and Vomiting Colicky Pain Constipation/ intestinal obstruction Urinary Retention / Hydroureteronephrosis / Obstructive Uropathy.

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 limbs

Constitutional symptoms: Fatigue Weakness Fever Loss of Appetite Loss of weight Back Pain

INVESTIGATIONS FOR RETROPERITONEAL MASS

INVESTIGATION

1) Routine blood investigations: to know about i) CBC : Anemia, Leukocytosis ii) Serum Creatinine : Obstructive Uropathy iii) Liver function test iv) Effect of paraneoplastic syndrome

RBS- HypoglycemiaS. Calcium- Hypercalcemia Blood /Urinary- Catecholamines

v) Tumor markers :- AFP, Beta-HCG, LDH

2) Chest X ray PA view:- Lung metastasis

3) Plane X ray abdomen:- signs of intestinal obstruction, obliterated psoas shadow, calcification of tumor mass.

4) USG abdomen : nature of mass(solid/cystic) and relation to the adjacent structures.

5) CT / MRI abdomen and pelvis Site, size , relationship to adjacent organs , planning for operation , metastases can be determined.

Contrast enhanced CT has got better tissue delineation

6) PET-CT No defined role in primary level FDG uptake does correlate with

tumor grade in soft tissue sarcoma. Detect metastatic disease.

7) Chest CT

8) ARTERIOGRAPHYFINDING SUGGESTIVE OF NEOPLASIA INCLUDES :

Neovascularization

Tumor blush

Vessel Encasement

Demonstration of extra-renal artery helpful in kidney sparing surgery.

A DOMINANT LUMBER OR INTERCOSTAL ARTERIAL SUPPLY ADDS TO THE LIKELIHOOD THAT THE TUMOR HAS A RETROPERITONEAL ORIGIN.

9) CT/USG guided/Laparoscopic core biopsy :Indications of preoperative biopsy An unusual appearing mass non-resectable tumor Distant metastasis Patient being considered for

neoadjuvant chemotherapy

10) FNAC : has got limited role.

11) IVU ;- obstruction and displacement of kidney and ureter, distortion of renal pelvis and bladder compression.

12) Confirmation of diagnosis is only by tissue biopsy.

Retroperitoneal Sarcoma Rare tumors , only 1–2 % of all solid

malignancies (10–20 % of all sarcomas are retroperitoneal )

The peak incidence is in the fifth decade of life

Common Types :• liposarcoma - 33%• leiomyosarcoma;• malignant fibrous histiocytoma (MFH).

Present late, because arise in the large potential spaces of the retroperitoneum and can grow very large without producing symptoms.

Nonspecific symptoms - abdominal fullness, dull aching pain.

The overall prognosis is worse than that with extremity sarcomas

1) LIPOSARCOMA:well differentiated liposarcoma showing huge heterogeneous mass with predominantly fat attenuation.

2) LIPOMA: T1 weighted MRI. Homogenous high signal intensity mass.

Most common retroperitoneal malignancy, about 33%

age group : 40–70-yearfrequently manifests with

extra-nodal disease in the liver, spleen, or bowel, often at an advanced stage.

History of fever , myalgia , night sweats , weight loss

Para aortic lymph nodes involved in 25% with Hodgkin lymphoma and 55% with non-Hodgkin lymphoma.

LYMPHOMA

NHL

Germ cell tumor < 10% of Teratomas are found in the

retroperitoneum. Third most common tumor in the

retroperitoneum in children, after neuroblastoma and Wilm’s tumor

Females > Male, 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 (tooth like or well defined) and fat can be seen in 56% and 93% of cases, respectively

TERATOMA

Caused by trauma , blood dyscrasia , anticoagulation therapy , rupture of an abdominal aortic aneurysm , or interventional or surgical procedures .

Occasionally, the heterogeneous appearance on CE-CT images can be confused with a sarcoma

the well-defined margin, the absence of contrast enhancement, the changing appearance with t ime, a progressive decrease in size,

…..dist inguish retroperitoneal hematoma from sarcoma

low signal intensity on MR images because of hemosiderin deposit ion.

RETROPERITONEAL HEMATOMA

A collection of extravasated urine that is found secondary to trauma or iatrogenic causes.

A well-defined cystic lesion is seen in the retroperitoneum, more commonly in the peri-renal space.

CT shows a well-defined fluid

collection with progressively increasing attenuation caused by contrast-enhanced urine entering the urinoma

URINOMA

A fibro-inflammatory mass envelops and potentially obstructs retroperitoneal structures.

Fibrous, whitish plaque encases aorta, IVC & their major branches, ureters, other retroperitoneal structures,may involve GIT.

Idiopathic-70%(Ormond’s disease) Definitive etiology in 30%.

Symptoms - dull, poorly localized, non colicky pain in flank, back, or lower abdomen. Unrelated to posture

MRI can distinguish from other pathology

RETROPERITONEAL FIBROSIS