Pathology of Neoplastic Disease Flashcards
Metastases
‘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
Metastatic Cascade
- Primary tumour formation
- Localised invasion
- Intravasation
- Transport of CTCs through circulation
- Arrest in micro-vessels of various organs
- Extravasation
- Formation of micro-metastasis
- Colonisation
Intravasation
○ Cancer cells detach from tumour mass and penetrate endothelial walls of blood cells
○ Then referred to as Circulating Tumour Cells (CTCs)
○ Interact with platelets
Extravasation
Leakage of fluids from vein into surrounding tissue
Colonisation
Formation of macro-metastases
Pathways of Metastases
Trans-coelomic
Lymphatic
Haematogenous
Trans-coelomic Pathway
○ Cancers that arise on the surface of abdominal and thoracic structures
○ Confined to peritoneum, pericardium and pleural cavity
Mesotheliomas
Ovarian/pancreatic adenocarcinomas
○ Carcinomatosis
Lymphatic Pathway
Lymph node closest to tumour is colonised earliest and develop the largest tumour masses
E.g. adenocarcinoma of intestine
Haematogenous Pathway
○ 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
Common Metastatic Sites
Lungs
Liver, spleen, kidneys
Bone
Brain, adrenal glands
Lung Metasteses Examples
○ Osteosarcoma
○ Haemangiosarcoma
○ Melanoma
○ Mammary tumours
Others (e.g. thyroid, tonsillar and pancreatic)
Liver, spleen, kidneys Metastases Examples
Mast cell tumour
Haemangiosarcoma
Bone Metastases Examples
Mammary gland tumours
Prostatic Carcinoma
Urinary bladder tumours
Brain, adrenal glands Metastases Example
Bronchogenic carcinoma
Consequences of Neoplasia
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
Cancer Cachexia
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)
Endocrine Neoplasm
Functioning endocrine tumour
E.g. Hypoglycaemia due to insulinoma
Non-endocrine Neoplasm
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
Hypertrophic Pulmonary Osteopathy
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)
Vascular and haematological disorders associated with neoplasia
○ Anaemia
○ Thrombocytopenia
○ Hyperviscocity syndrome
○ Leucocytosis
Other Paraneoplastic Clinical Syndromes
- Epidermal necrosis:
○ Pancreatic and hepatic tumours - Nodular dermatofibrosis:
○ Renal adenocarcinoma - Alopecia:
○ Pancreatic carcinoma - Exfoliative dermatitis:
○ Thymoma - Myasthenia gravis:
○ Thymoma
○ Hepatic carcinoma
○ Osteogenic sarcoma
