Pelvic Metastases

Pelvic Metastases
Atif Zaheer, MD
Assistant Professor
The Russell H. Morgan Department of
Radiology and Radiological Science
Johns Hopkins University
Baltimore, MD
Lymphatic tumor spread
• Lymph vessels larger than small capillaries
• Easy movement of tumor cells (No basement
membrane & fewer intercellular junctions)
• Slower flow velocities than capillaries
• Lymph fluid similar to interstitial fluid and
promotes tumor cell viability
Metastases in the pelvis
•
•
•
•
•
Lymphatic
Lymphatic
Lymphatic
Osseous
Visceral
N
T
M
Lymphatic tumor spread
•
•
•
•
•
•
•
•
Ovary
Uterus
Cervix
Vagina
Prostate
Bladder
Rectal
Anus
Pelvis: Common iliac lymph nodes
1
2
3
1 a
2
v
3
1= Lateral
2= Medial
3= Middle
Case Example
External iliac lymph nodes
1
a 2
v
3
1
2
3
1= Lateral
2= Middle
3= Medial
Case Example
Internal iliac lymph nodes
3
1
3
2
1
1= Lateral sacral
2= Presacral
3= Anterior
2
Inguinal nodes
1
a 2
v
1
2
1= Superficial
2= Deep
Inguinal nodes
Normal sites of lymphatic drainage of
Pelvic organs
Organ
Lymphatic drainage
Prostate
Obturator– Most frequently
Int. & ext. iliac → Common iliac
Pre-sacral
Bladder
Ant. Lateral paravesical and pre-sacral initially
Followed by
Obturator & ext. iliac → Common iliac
Rectal
Pararectal/mesorectal initially
Upper ½ -- Pararectal at origin of inf. Mesenteric artery via Superior rectal
artery chain
Lower ½ -- Int. iliac via middle rectal artery chain
Anus
Above dentate line– Perirectal, int. iliac
Below dentate line– Superficial inguinal
Normal sites of lymphatic drainage of
Pelvic organs
Organ
Lymphatic Drainage
Ovary
Para-aortic via ovarian vessel chain, Left to the renal vein and Right to IVC
at L1
External and common iliac, obturator via broad ligament
Superficial inguinal via round ligament
Uterus
Fundus--Para-aortic via ovarian vessel chain
Body-- Int. & ext. iliac → Common iliac
Fallopian tube– Superficial inguinal via round ligament
Cervix
Parametrial, obturator & pre-sacral initially
Int. & ext. iliac → Common iliac
Vagina
Upper 1/3 --Int. & ext iliac
Middle 1/3– Int. iliac
Lower 1/3– Superficial inguinal
Imaging features of lymph node
metastases
• Size
– Overlap
– Site specific
•
•
•
•
•
Common iliac = 9mm
Internal iliac = 7 mm
External iliac = 10 mm
Obturator = 8 mm
Inguinal = 15 mm
– Tumor specific (e.g., 60% of involved nodes in
rectal cancer are <5mm)
Imaging features of lymph node
metastases
• Shape
Imaging features of lymph node
metastases
• Site
– Drainage site
– e.g., Obturator node for Bladder, prostate or
cervical cancer
Imaging features of lymph node
metastases
• Clustering, asymmetry and contour
Imaging features of lymph node
metastases
• Signal intensity
– Similar to primary tumor
– Necrosis
Prostate Cancer
Prostate Cancer
Extracapsular disease w/
lymphadenopathy
Prostate Ca Gleason 7
s/p prostatectomy with rising PSA
12/15/09
Prostate Cancer
Therapeutic options for prostate
cancer
• Pelvic lymph node metastases strongest
predictor of disease recurrence and
progression
• Presence of metastases --difference between
local and systemic therapy.
Ultrasmall superparamagnetic iron
oxide (USPIO)
N Engl J Med. 2003 Jun 19;348(25):2491-9. Erratum in: N Engl J Med. 2003 Sep
4;349(10):1010.
Bladder Cancer
• Higher N stage correlates with higher T stage
• +ive nodes →Chemo/Chemo + Radxn
• ↑nodes → ↓ prognosis
– N0= No regional nodes
– N1= Single node≤2 cm
– N2= >2 cm ≤ 5 cm, or multiple nodes
– N3= > 5 cm
Bladder Cancer
Paravesicle
Paravesicle
Bladder Cancer nodal
metastasis
Bladder Cancer nodal
metastasis
Bladder Cancer nodal
metastasis
Bladder Cancer nodal
metastasis M1
Rectal Cancer
• Tumor confined to bowel wall= 80% 5-yr
survival
• Transmural dz = 50% 5-yr survival
• Lymph node involvement= 12 % 5-yr survival
• Upper and lower ½
• Mesorectal nodes
– N0= No regional nodes
– N1=1-3 regional nodes
– N2= >4 regional nodes
Rectal Cancer
Mesorectal
Mesorectal
Rectal Cancer w/ mesorectal nodes
Rectal Cancer N1
Rectal Cancer N2
Rectal Cancer M1
Anal Cancer
Anal Cancer
Mesorectal
Mesorectal
Anal Cancer nodal metastasis
Anal Ca nodal metastasis M1
Ovary
• Nodal metastases=upstaging to IIIA
• Tx with chemotherapy
Ovarian cancer
Endometrial Cancer
• Probability of lymph node metastases α
histological grade and depth of myometrial
invasion
• Pelvic nodal metastases more common than
para-aortic…but..
• Para-aortic adenopathy is regional and can occur
in isolation (esp. L. para-aortic)
• Upper & lower pathways
• Radxn and chemo for LN mets
Endometrial Cancer
Endometrial Cancer
Cervix
• Parametrial, obturator & pre-sacral initially
• Int. & ext. iliac → Common iliac
• Para-aortic only occurs when pelvic nodes
involved
• Sx removal improves survival
• PET recommended in presence of LN to
assess further dz.
Cervical Cancer
Cervical Cancer
Cervical Cancer
Cervical Cancer M1
Vaginal Cancer
• Upper 1/3 --Int. & ext iliac
• Middle 1/3– Int. iliac
• Lower 1/3– Superficial inguinal
• EBRT to LN
Vaginal Cancer
Vaginal Cancer
Vaginal Cancer
Penile Cancer
Imaging Pitfalls
• Hyperplasia
• Anatomic structures (vessels)
• Post surgical
– Hematomas
– Lymphocoeles
– Hernia plugs
Lymph node mimickers
Hernia Plug
Postoperative lymphoceles
Osseous Metastases
Osseous Metastases
• Direct invasion or hematogenous spread
• Most common in Prostate Ca and rarely in
Ovarian Ca
• MRI more sensitive than Tc99m MDP (82-91%
vs. 71-84%)
– Early marrow involvement before osteoblastic
stimulation
Osseous Metastases
• Technique
– T1 and STIR
– Contrast helpful
• Metastases
– Low on T1
– High on STIR
– Sclerotic mets low on both
Spinal Metastases
Prostate Cancer
12/18/09
6/20/08
Muscle and sacral invasion in a 44-year-old woman with
clinical and imaging stage IV cervical cancer
Osseous metastases
Pitfalls
•
•
•
•
•
•
•
•
•
Normal red marrow
Bone marrow reconversion
Radiotherapy effect
Osteoporotic vertebral body collapse
Hemangiomas
Benign bone island
Subchondral cysts
Nutrient foramina
Pagets Disease
Normal
Sickle cell disease
Case Courtesy: Dr. Avneesh Chhabra
Treated leukemia
Case Courtesy: Dr. Avneesh Chhabra
Post radiation changes
Osteoporotic fracture
Pelvic Visceral Metastases
Pelvic Visceral Metastases
• Ovary commonest organ (e.g., Krukenberg)
– 2% of gastric ca
– Precedes diagnosis of primary tumor in 20%
– 1’ tumor frequently multilocular than 2’ on MRI
• Breast
– 50% pts w/ breast Ca have ovarian mets on autopsy
– Uterine mets (enlarged myometrium)
• Melanoma
– Intermediate to high signal on T1
Krukenberg tumor primary colon
METASTATIC POORLY DIFFERENTIATED
CARCINOMA WITH EXTENSIVE NECROSIS.
Summary
• Lymph node involvement dictates tumor
stage, therapy and prognosis
• Regional and non-regional lymphatic
pathways for accurate staging
• Remember to look for osseous metastases
but keep in mind the pitfalls
• Consider visceral metastases with known
primary tumor