Unit 12 - Primary Retroperitoneal Tumors

What is a primary retroperitoneal tumor?

An independent origination anywhere within retroperitoneal space

Most primary retroperitoneal tumors are ________.

Malignant

Neurogenic tumors can be ________ or _________.

Benign or malignant

Where are neurogenic tumors normally found?

Spinal area - arising from nerve roots

What is the US appearance of a Neurogenic tumor?

Variable echo pattern

Most common primary retroperitoneal tumor?

Lymphoma

What is the US appearance of a Lymphoma?

• Cortex > 3 mm

• Round, hypoechoic masses to anechoic masses with enhancement

• Color Doppler – increased intranodal vascularity

What should you evaluate when you suspect a Lymphoma?

• Determine if lymphadenopathy

  • Splenic, hepatic & renal hilum

  • Para-aortic, origin of Celiac trunk & SMA

  • 90% detection when nodes > 2 cm

What is this image showing?

A malignant lymph node

What is this image showing?

High RI in a malignant lymph node

What is the primary criteria of a malignant lymph node vs. a benign lymph node.

• Size > 2cm

• Cortex > 3mm

• Round

• RI > 0.70

What is a Leiomyosarcoma?

Smooth muscle tissue of small blood vessels or within the GI tract & extend into retroperitoneum

What is the US appearance of a Leiomyosarcoma?

• Large mass with complex echo pattern

• Undergo necrosis & cystic degeneration

What is a Liposarcoma?

• Large Lipoblasts & fat cells

  • connective tissue cell that develops into a fat cell

What is the US appearance of a Liposarcoma?

Highly reflective echo pattern

What is a Fibrosarcoma?

Collagen producing fibroblast

What is a Rhabdomyosarcoma?

Striated muscle cells

What 2 masses are both highly invasive?

1. Fibrosarcoma

2. Rhabdomyosarcoma

What 2 masses may infiltrate muscle & surrounding tissues?

1. Fibrosarcoma

2. Rhabdomyosarcoma

What is the US appearance of a Fibrosarcoma & Rhabdomyosarcoma?

• Highly reflective echo pattern

• May extend across ML & appear similar to Lymphomas

Germ cell tumors can be _______ & _________.

Benign & malignant

Teratomatous tumors =

Teratoma

What is the US appearance of a Teratoma tumor?

• Mixed elements

• Complex echo pattern

• Heterogeneous with

  • Solid areas

  • Calcifications

  • Cystic spaces

What is this image showing?

A Teratoma tumor