Neoplasia 1&2 Flashcards
Define malignant neoplasia
The abnormal growth of cells, which persist after the initiating stimulus has been removed and invades and spreads to distant sites (metastasis)
Define benign neoplasia
The abnormal growth of cells, which persists after the initiating stimulus has been removed
Describe the physical difference in benign and malignant neoplasms
Benign neoplasms are rounded masses due to the pushing growth, and remain at the site of origin
Malignant neoplasms are irregular masses due to infiltrative growth, and may spread to distant sites forming secondary growths (metastases)
A mutation in which genes can cause neoplasia?
Proto-oncogenes (permanently activated to oncogenes) or Tumour Suppressor Genes (permanently inactivated)
What key differences do neoplastic cells have from normal cells?
Self sufficient growth signals Resistance to anti-growth signals Grow indefinitely Induce new blood vessels Resistance to apoptosis Invade and produce metastases
Describe the clonality of neoplasms
They are monoclonal as the cell population descends from a common ancestral cell which originally acquired the mutation.
How do benign and malignant tumours differ?
Benign: pleomorphism (variation in size/shape) is minimal, low mitotic count, mitoses have normal form, retention of tissue specialisation (well differentiated)
Malignant: variable pleomorphism, higher mitotic count, mitoses may have abnormal forms, variable loss of tissue specialisation (well to poorly differentiated)
Define tumour
Any clinically detectable lump or swelling
Define cancer
Any malignant neoplasm
Distinguish between in-situ and malignancy
In-situ has all the features of a malignant neoplasm but there is no invasion through the basement membrane.
How are neoplasms classified/named?
By whether they are benign or malignant, and by tissue type.
What is Squamous papilloma
A benign neoplasm of stratified squamous epithelium.
Tumour has finger like projections.
Eg. Skin, buccal mucosa
What is transitional papilloma?
Benign neoplasm of transitional epithelium
Eg. Bladder mucosa
What is an adenoma?
Benign neoplasm of glandular epithelium
Eg. Adenomatous polyp of colon
What is squamous cell carcinoma?
Malignant neoplasm of squamous epithelium
Eg. Skin, larynx, oesophagus
What is transitional cell carcinoma?
Malignant neoplasm of transitional epithelium
Eg. Bladder, uterus
What is adenocarcinoma?
Malignant neoplasm of glandular epithelium eg. Stomach, colon, lung, prostate, breast, pancreas
What is basal cell carcinoma?
Malignant neoplasm of basal cells eg. in skin
What is leiomyoma?
Benign neoplasm of smooth muscle
What is leiomyosarcoma?
Malignant neoplasm of smooth muscle
What is fibroma?
Benign neoplasm of fibrous tissue
What is fibrosarcoma?
Malignant neoplasm of fibrous tissue
What is osteoma?
Benign neoplasm of bone
What is osteosarcoma?
Malignant neoplasm of bone
What is chondroma?
Benign neoplasm of cartilage
What is chondrosarcoma?
Malignant neoplasm of cartilage
What is lipoma?
Benign neoplasm of adipose tissue
What is liposarcoma?
Malignant neoplasm of adipose tissue
What is neurofibroma?
A benign neoplasm of nervous tissue
What is neurofibrosarcoma
A malignant neoplasm of nervous tissue
What is neurilemmoma?
Benign neoplasm of nerve sheath
What is neurilemmosarcoma?
Malignant neoplasm of nerve sheath
What is giloma?
Benign neoplasm of glial cells
What is malignant giloma
Malignant neoplasm of glial cells
What is lymphoma?
Malignant neoplasm in lymphoid (usually is lymph nodes)
What is leukaemia?
Malignant neoplasm of haematopoietic cells in bone marrow
What is myeloma?
Malignant neoplasm of plasma cells in bone marrow
What is malignant teratoma?
Malignant germ cell neoplasm of the testis
What is benign teratoma?
Benign germ cell neoplasm of the ovaries
What is the common name for benign teratoma?
Dermoid cyst
Define oncology
The study and treatment of tumours
What is a cystadenoma?
A cystic adenoma (benign)
What are polyps?
A benign tumour with a stalk, protruding from the mucus membrane
What is rhabdomyosarcoma?
A malignant neoplasm arising in skeletal muscle
What is haemangioma?
Benign tumour of the endothelial cells that line blood vessels, leads to increased number of normal or abnormal vessels filled with blood.
What is angiosarcoma?
Malignant tumour of endothelial cells lining vessel walls (blood or lymph vessels)
Can be haemangiosarcoma/lymphangiosarcoma
What is mesothelioma?
Malignant tumour in the mesothelium (most common site is pleura), most commonly caused by asbestos.
What is meningioma?
Tumour arising from the meninges. Usually benign, can be malignant
What is rhabdomyoma?
A benign neoplasm arising in skeletal muscle
What is hepatocellular carcinoma?
Malignant tumour in the liver. Most are secondary to viral hepatitis infection or cirrhosis
What is a naevus?
A chronic lesion of the skin/mucosa (birthmarks).
25% of malignant melanomas arise from pre-existing naevi
What is melanoma?
Malignant neoplasm of melanocytes, usually in skin, CNS be in bowel or eye.
Primary cause is UV exposure
What is hamartoma?
A benign tumour-like malformation made up of an abnormal mixture of cells and tissue.
A developmental error
Define invasion
The ability of cells to break through the basement membrane and spread.
Define metastasis
The spread of a malignant tumour to a distant site
What mechanisms facilitate invasion and metastasis?
Altered cell adhesion
Altered enzyme synthesis and interaction
Angiogenesis
How do metastatic cells alter their adhesion to facilitate invasion and metastasis?
Decrease cell-cell interactions by decreasing Cadherin expression (which usually binds cells together).
Decrease cell-stroma interactions by decreasing integrin expression, allows for cell movement.
How do metastatic cells alter enzyme synthesis and interaction to facilitate invasion and metastasis?
They synthesise and release Matrix Matalloproteinases which digest collagen, allowing the metastatic cells to digest the EMC and move to a break through the basement membrane.
How does angiogenesis occur in tumours to facilitate invasion and metastasis?
When a tumour reaches 1-2mm^3 growth is halted due to lack of nutrients & O2. Hypoxic micro-environment causes upregulation of pro-angiogenesis factors (eg. Angiopoietin, VEGF).
These cause growth of new blood vessels, allows for continued growth of tumour and opportunities to enter the blood stream.
What are the most common sites of metastasis?
Lymphatic system
Vascular system to the lungs, liver, bone, brain
What type of neoplasms are likely to metastasise via lymphatics?
Carcinomas
What can metastasis in bone cause?
Destruction of the bone, leading to pathological fractures.
Production of dense bone (osteosclerosis)
What local effects can benign neoplasms have?
Compression of structures leading to pressure atrophy or an altered function.
Partial or complete obstruction of hollow viscus.
Ulceration of surface mucosa.
Space occupying lesion in the brain.
What local effects can malignant neoplasms have?
Destruction of surrounding tissue.
Partial or complete obstruction or constriction of hollow viscus.
Ulceration.
Infiltration around and into nerves, blood vessels and lymphatics.
Space occupying lesions in the brain.
What haematological systemic effects can neoplasms have?
Anaemia due to malignant infiltration of bone marrow.
Low WBCs and platelets due malignant infiltration of bone marrow and the effects of treatments.
Thrombosis due to carcinoma of pancreas.
What endocrine systemic effects can neoplasms have?
Excessive secretion due to neoplasms of endocrine glands.
Ectopic secretion eg. ACTH by small cell carcinomas of the bronchus.
What systemic effects can neoplasms have on the skin?
Increased pigmentation (carcinomas).
Pruritis (itchiness).
Herpes zoster (lymphoma).
Dermatomyositis (bronchial carcinoma).
What neuromuscular systemic effects can neoplasms have?
Problems with balance.
Sensory/sensorimotor neuropathies.
Myopathy and myasthenia.
Progressive multi focal leucoencepalopathy.
What systemic effects can neoplasms have?
Haematological effects Endocrine effects Skin effects Neuromuscular effects Cachexia Malaise Pyrexia
What is cachexia?
Loss of weight, muscle atrophy, loss of appetite.
What is malaise?
A feeling of general discomfort or uneasiness
What is pyrexia?
Fever
