Retroperitoneum

Question 1

Primary ddx for solid retroperitoneal mass (5)

Answer 1

1) Lymphoma
2) Mets
3) Sarcoma - liposarcoma, leiomyosarcoma
4) Neurogenic - including paraganglioma
5) Germ cell** (extra-gonadal, often calcified with fat)
6) Extra-medullary hematopoiesis

Question 2

Non-neoplastic processes of the retroperitoneum (3)

Answer 2

1) Retroperitoneal fibrosis/IgG4
2) Extra-medullary hematopoiesis
3) Erdheim-Chester (rare)

Question 3

Most common primary malignancy of the IVC

Answer 3

Leiomyosarcoma

can also see liposarcoma