2. Main Routes of Spread of
tumours
• Direct spread
• Lymphatics
• Vascular spread
• Transcoelomic spread
• Perineural spread
3. Direct invasion
• Growth of cancers is accompanied by
progressive infiltration, invasion and
destruction by the surrounding tissue.
• In general they are poorly demarcate by
surrounding normal tissue and well defined
cleavage plane is lacking.
4. Mechanism of tumour cell
invasion and metastasis
• Factors increasing cell mobility
• Decreased adhererance of tumour cells
• Increased growth factor secretion
• Increased secretion of autocrine motility factor
• Failure to synthesise basement membrane
• Factors for facilitation of movement through stroma
• Secretion of collagenase, cathepsin B, gelatinase
• Stimulation of stromal cells to secrete stromelysin & alternative
extracellular matrix
• Factors improving tumour cell survival and spread
5. Metastasis is mainly by
• Lymphatic spread
• Haematogenous spread
• Transcoelomic spread
6. Lymphatic spread
• Carcinomas generally spreads via lymphatics first.
But sarcomas can use this route too.
• The pattern of lymph node involvement follows the
natural routes of drainage.
• Carcinoma of breast (upper outer quadrant) spread
to axillary lymph nodes, the inner quadrant drain
through the nodes along the internal mammary
artery. Later supraclavicular and infraclavicular
nodes may become involved.
10. Skip metastasis
• Local lymph nodes may be bypassed due
to venous lymphatic anastomosis or
because the inflammation or radiation has
obliterated the channels.
11. • Regional nodes act as a barrier to further
spread of the tumour, at least for a time.
• The cells, after arrest within the node, may
be destroyed.
• Drainage of tumour cell debris or tumour cell
antigens, or both can induce reactive
changes.
• The enlargement of the nodes may be due
to
– 1. Spread of the cancer cells
– 2. Reactive hyperplasia
13. Via blood stream
spread
• As tumour emboli
– Osteosarcomas
metastatising to the
lungs
– Gastrointestinal
malignancies
metastatising to the
liver
14. Permeation
• Cords of cells grow along the blood
vessels
– Eg. In renal cell carcinoma the malignant cell
cords grow along the vessel walls, renal vein
and IVC
15. Haematogenous spread
• Typical for sarcomas but also used by the
carcinomas.
• Arteries: due to thicker walls are less readily
penetrated. But is seen when a tumour pass
through pulmonary capillary beds or pulmonary
arterio-venous shunts or when pulmonary
metastasis give rise to tumour emboli.
• Venous invasion follow venous flow draining the
site of neoplasm. Eg. Liver and lung.( all portal
drainage to the liver and all caval blood flows to
the lungs)
• Cancers arising in close proximity to the vertebral
column often embolise through the paravertebral
plexus. Eg: thyroid and prostate carcinomas
16. Haematogenous spread
contd…..
• Certain cancers have a propensity for venous
invasion.
• Renal cell carcinoma invades branches of renal vein
then renal vein and grow along the IVC in a snake
like fashion some times reaching the right side of the
heart.
• Hepatocellular carcinoma often penetrate the portal
vein
• Such IV growth may not be accompanied by
widespread dissemination.
17. Secondary
carcinoma of
lung
• These tan-white nodules
are characteristic for
metastatic carcinoma.
Metastases to the lungs
are more common even
than primary lung
neoplasms simply
because so many other
primary tumours can
metastasise to the lungs.
21. • Certain types of tumours have a characteristic
patterns of spread. Eg. Prostatic ca is often
spread to bone
• It is thought that the malignant cells and the
target organ must express mutually
compatible receptors and cell surface
adhesion molecules which facilitate cellular
anchorage and growth promotion
• Hepatic metastasis: portal circulation
• Pulmonary metastasis: from systemic
circulation
23. Transcoelomic spread contd…
• Krukenberg tumour
• Gastric carcinoma with secondary deposits in the
ovary and pouch of Douglas
• Colonic carcinoma with secondary deposits in the
ovary and pouch of Douglas
24. Transcoelomic spread
• Tumour cells may remain confined to the
surface of the abdominal viscera without
penetrating into the substance.
• Some times the mucous secreting
tumours of the ovarian or appendiceal
carcinoma fill the peritoneal cavity with
gelatinous neoplastic mass referred to as
pseudomyxoma peritonei.
26. • Breast and lung tumours commonly
involve pleural space and cause
pleural effusion
• Ovarian and gastric tumours are
responsible for peritoneal invovment
and cause malignant ascitis.
• There is commonly an inflammatory
response in the lining with the
accumulation of protein rich fluid and
inflammatory cells, proliferation of
mesothelial cells and haemorhage
