retroperitoneum Flashcards
What are the causes of spontaneous retroperitoneal hemorrhage in the following spaces?
Anterior pararenal
Perirenal
Posterior pararenal
Ant - hemorrhagic pancreatitis
Peri - AAA, RCC, AML, polyarteritis nodosa
Post - anticoagulation
What is the most common nontraumatic cause of RPH?
Ruptured aortic aneurysm
What are the adrenal tumors that can bleed
Primary/metastatic tumors myelolipoma pheochromocytoma cyst abscess
What are the two most common renal tumors that bleed
AML, usually >4cm
RCC
What is a urinoma?
Mass formed by encapsulated extravasated urine
What is a page kidney
Mass effect on the renal parenchyma activates the RAS system resulting in significant hypertension
What are the two outcomes with urine leakage intot he retroperitoneum
Retroperitoneal fibrosis
Urinoma
What are the most common causes of retroperitoneal abscess in the
anterior pararenal space
perinephric
posterior pararenal
Ant - pancreatitis
Peri - UTI
Post - osteomyelitis
What is a lymphocele?
discrete collections of chylous fluid found after inadequate ligation of disrupted lymphatic vessels
On CT, how does one differentiate between abscess and lymphocele
Lymphocele will be negative houndsfield due to the fat content
How does fluid in the prevesicle extraperitoneal space present?
Molar tooth shaped
Most common cause of chyluria? Other causes?
Filariasis
retroperitoneal malignancy, trauma, surgery, TB, LAM
What are the radiographic findings of chyluria?
Lymphangiography - increase in number, size, and tortuosity of retroperitoneal vessels with retrograde flow of contrast into the renal lymphatics
What is ormands disease?
Idiopathic retroperitoneal fibrosis encasing both ureters
What are the causes of retroperitoneal fibrosis?
Meds - methysergide, ergotamine, methyldopa
Retroperitoneal fluid
Inflammatory disease
Surgery/Radiation
Desomplastic response to malignancy
Lymphoma, sarcoma
Breast, stomach, colon, prostate, kidney, lung
What are features of retroperitoneal fibrosis that suggest malignancy?
Lobulated contour, ill defined borders, displacement of great vessels away from spine
Enhancement of the retroperitoneal plaque suggests what?
Malignancy
What distinguishes malignant RPF on MRI?
bright on T2
What are the size criteria for enlarged LN in the
retrocrural
retroperitoneum
pelvis
> 6mm
10mm
13mm
Which LN chain do the following drain to
pelvic organs
testes and ovaries
retroperitoneal
internal/external iliac chains to the common iliac chains
ipsilateral retroperitoneal nodes in region of great vessels
regional nodes along aorta and IVC
What are the differences in lymph node appearance in NHL and HL
NHL - significantly enlarged nodes or conglomerate masses
HL - discrete enlargement of individual nodes
Left paraaortic mass inferior to left renal vein raises suspicion of what
Metastatic testicular cancer
Name 3 common benign and malignant retroperitoneal tumors
Benign - lipoma, nerve sheath tumor, lymphangioma
Malignant - liposarcoma, leiomyosarcoma, MFH
Most common malignant tumor in retroperitoneum?
lymphoma
How does a neurilemoma look in CT? neurofibroma?
well defined oval mass with low density and areas of cystic degeneration and calcification
well defined ovoid masses with attn 20-25 with homogenous enhancement
Multiple symmetric low density masses along the courses of the peripheral nerves is classic for what disease
neurofibromatosis 1
Most common malignant retroperitoneal tumor? usual age group? if over 50?
Liposarcoma > leiomyosarcoma > MFH
30-50yo
MFH if over 50
Calcification is suggestive of what two malignant tumors? central necrosis? elongated appearance and spinal erosion?
MFH and mature teratoma
leiomyosarcoma
neural sheath tumors
Difference between lipoma and liposarcoma?
Liposarcoma has soft tissue component
Most common type of retroperitoneal liposarcoma?
Myxoid - large amounts of connective tissue and little lipid
can mimic abscess or muscle
