Retroperitoneum - Part 5 Flashcards
What are the functions of the lymph node? (2)
- Filter the lymph of debris and organisms
2. Form lymphocytes and antibodies to fight infection
What is the US appearance of a normal lymph node? (6)
- Hypo echoic solid mass
- Hyper echoic fatty center
- Smooth margins
- Oval shape
- Internal vascular blood flow especially at the hilum
- Usually measures less than 1cm
What is the US appearance of retroperitoneal masses? (6)
- Hyper echoic to hypo echoic mass(es)
- Irregular wall margins
- Anterior displacement of the kidneys, IVC, aorta and mesenteric
vessels - Deformity of the IVC and urinary bladder
- Obstruction of the urinary tract or biliary system
- Loss of organ definition
Lymphadenopathy
Any disorder characterized by a localized or generalized enlargement of the lymph nodes or lymph vessels
What is the US appearance of lymphadenopathy? (4)
- Hypo echoic mass
- May appear complex
- Smooth or irregular margins
- Exceeds 1cm in size
What are 4 differential diagnosis for lymphadenopathy?
- Lipoma
- Retroperitoneal fibrosis
- Retroperitoneal hemorrhage
- Horseshoe kidney
Lymphocele
A fluid collection containing lymph from an injured lymph vessel
What is lymphocele commonly associated with?
With organ transplant and lymph node removal
What is the US appearance for lymphocele? (5)
- Anechoic fluid collection
- Round or oval in shape
- Well-defined borders
- Frequently contain septations
- Posterior acoustic enhancement
What are 4 differential diagnosis for lymphocele?
- Hematoma
- Urinoma
- Ascites
- Abscess
Retroperitoneal abscess
A collection of pus between the peritoneum and the posterior abdominal wall
What is the US appearance for retroperitoneal abscess? (4)
- Hypo echoic or complex mass
- Irregular margins
- May demonstrate posterior acoustic shadowing
- Mass takes on the shape of the space
What are 4 differential diagnosis of retroperitoneal abscess?
- Hemorrhage
- Lymphadenopathy
- Retroperitoneal fibrosis
- Horseshoe kidney
Retroperitoneal fibrosis
A chronic inflammatory process in which fibrotic tissue surrounds the large blood vessels located in the lumbar area
What is the cause of retroperitoneal fibrosis?
Usually idiopathic