Pathology of Neoplastic Disease

Question 1

Metastases

Answer 1

‘Spread’ of a tumour to a new anatomical location away from the primary tumour
Formed by malignant cells which have left the primary tumour and travelled vu blood and lymphatic vessels

90% of deaths from cancer are due to metastases

Question 2

Metastatic Cascade

Answer 2

1. Primary tumour formation
2. Localised invasion
3. Intravasation
4. Transport of CTCs through circulation
5. Arrest in micro-vessels of various organs
6. Extravasation
7. Formation of micro-metastasis
8. Colonisation

Question 3

Intravasation

Answer 3

○ Cancer cells detach from tumour mass and penetrate endothelial walls of blood cells
○ Then referred to as Circulating Tumour Cells (CTCs)
○ Interact with platelets

Question 4

Extravasation

Answer 4

Leakage of fluids from vein into surrounding tissue

Question 5

Colonisation

Answer 5

Formation of macro-metastases

Question 6

Pathways of Metastases

Answer 6

Trans-coelomic
Lymphatic
Haematogenous

Question 7

Trans-coelomic Pathway

Answer 7

○ Cancers that arise on the surface of abdominal and thoracic structures
○ Confined to peritoneum, pericardium and pleural cavity
Mesotheliomas
Ovarian/pancreatic adenocarcinomas
○ Carcinomatosis

Question 8

Lymphatic Pathway

Answer 8

Lymph node closest to tumour is colonised earliest and develop the largest tumour masses
E.g. adenocarcinoma of intestine

Question 9

Haematogenous Pathway

Answer 9

○ Sarcomas tend to use this pathway more frequently than carcinomas
○ Tumour generally invade veins rather than arteries
Vein walls are thinner and easier to penetrate
○ Ultimately reach the vena cava and enter lungs and liver

Question 10

Common Metastatic Sites

Answer 10

Lungs
Liver, spleen, kidneys
Bone
Brain, adrenal glands

Question 11

Lung Metasteses Examples

Answer 11

○ Osteosarcoma
○ Haemangiosarcoma
○ Melanoma
○ Mammary tumours
Others (e.g. thyroid, tonsillar and pancreatic)

Question 12

Liver, spleen, kidneys Metastases Examples

Answer 12

Mast cell tumour
Haemangiosarcoma

Question 13

Bone Metastases Examples

Answer 13

Mammary gland tumours
Prostatic Carcinoma
Urinary bladder tumours

Question 14

Brain, adrenal glands Metastases Example

Answer 14

Bronchogenic carcinoma

Question 15

Consequences of Neoplasia

Answer 15

Direct Effect:
○ Space occupying lesion
○ Puts pressure on surrounding healthy tissue leading to necrosis
Indirect Effects:
○ Haematological complications
○ Endocrinological complications
○ Metabolic complications
○ These complications may be the main presenting clinical sign:
Cause profound clinical problem
Hallmark of a particular tumour
Can affect response to treatment with chemotherapy and/or surgery

Question 16

Cancer Cachexia

Answer 16

Weakness and wasting of the body due to neoplasia
Most common syndrome
Result of altered carbohydrate, protein and lipid metabolism
Complex pathogenesis due to:
○ TNF-a
○ Il-1
○ IL-6
○ Prostaglandins
Fever is caused by tumour induced production of cytokines (IL-1)

Question 17

Endocrine Neoplasm

Answer 17

Functioning endocrine tumour
E.g. Hypoglycaemia due to insulinoma

Question 18

Non-endocrine Neoplasm

Answer 18

Hormonally active substances not normally found in the tissue of tumour origin
E.g. Hyperglycaemia from tumour producing PTH-related protein
Causes bone and renal calcium resorption

Question 19

Hypertrophic Pulmonary Osteopathy

Answer 19

Rapid periosteal new bone growth affecting distal limbs
Most commonly associated with lung tumour
Primary or metastatic
Myelofibrosis
Overgrowth of non-neoplastic fibroblasts in the bone marrow
Impairs normal haematopoiesis
Results in cytopenias (low blood cells)

Question 20

Vascular and haematological disorders associated with neoplasia

Answer 20

○ Anaemia
○ Thrombocytopenia
○ Hyperviscocity syndrome
○ Leucocytosis

Question 21

Other Paraneoplastic Clinical Syndromes

Answer 21

• Epidermal necrosis:
  ○ Pancreatic and hepatic tumours
• Nodular dermatofibrosis:
  ○ Renal adenocarcinoma
• Alopecia:
  ○ Pancreatic carcinoma
• Exfoliative dermatitis:
  ○ Thymoma
• Myasthenia gravis:
  ○ Thymoma
  ○ Hepatic carcinoma
  ○ Osteogenic sarcoma