Pathology Definitions (from Glossary) 2016 Flashcards
Abscess
a collection of pus in an organ or tissue
Cellular adaptation
reversible cellular change occurring in response to environmental stress.
Each type of cellular adaptation may be classified as pathological or physiological
Adenocarcinoma
a malignant neoplasm showing histological features of glandular or secretory epithelium
Adenoma
a benign neoplasm showing histological features of glandular or secretoryepithelium.
Aetiology
the cause of a disease.
Alcoholic hepatitis
acute hepatitis induced by alcohol. A characteristic feature is the formation of Mallory bodies within the cytoplasm of injured hepatocytes.
Amorphous
lacking in cellular or tissue detail
Amphophilic
staining with both basic and acid dyes
Amyloids
abnormal proteins that form extracellular deposits that are resistant to proteolytic breakdown.
Anaemia
deficiency of red blood cells or haemoglobin in the blood.
Anaplasia
literally, to form backward.
A feature of malignant neoplasms, referring to loss of differentiation in relation to the tumour’s normal tissue counterpart.
Aneurysm
localised dilatation of the wall of an artery or of the heart, usually of the left ventricle.
Anoxia
complete deprivation of oxygen
Anthracosis
the presence of inhaled particles of coal dust in the lung that are engulfed by pulmonary macrophages and transported along lymphatic channels to lymph nodes in the hilum.
Apoptosis
regulated cell death affecting single cells in response to a variety of pathological and physiological stimuli.
Ascites
abnormal excessive fluid in the peritoneal cavity
Assman focus
focus of granulomatous inflammation in the apex of the lung seen in secondary tuberculosis.
Atheroembolus
an embolus originating from an atherosclerotic plaque, composed of lipid-rich debris
Atrophy
reduction in size of an organ, tissue or cell.
Barrett’s oesophagus
metaplasia of the stratified squamous epithelium in the lower oesophagus to simple columnar epithelium occurring in response to gastric reflux. Intraepithelial neoplasia (dysplasia) may develop in Barrett’s esophagus and give rise to adenocarcinoma. Patients with Barrett’s oesophagus undergo regular, lifelong endoscopic surveillance.
Basophilic
staining blue—purple due to avidity for the haematoxylin component of the H&E stain
Benign
a neoplasm which grows by non-destructive expansion and remains localised to its site of origin.
can be cured by local excision.
Histologically, closely resemble their cell of origin with normal or only mildly abnormal nuclei and low mitotic activity.
Biopsy
removal of tissue from the body during life for the purpose of pathological analysis
Bronchiectasis
a chronic inflammatory disease of the lung characterised by irreversible dilatation of
bronchi, and associated with recurrent or chronic pulmonary bacterial infections
Bronchiolitis
inflammation of bronchioles due to viral
infections and atypical bacterial pathogens such as mycoplasma.
Viral bronchiolitis is common in childhood.
Bulla
a large fluid—filled blister in the skin; a large cystically dilated airspace in the lung.
Calcification
the abnormal deposition of calcium in tissue.
Calculus
a stone forming inside the gallbladder or the urinary tract.
Carcinoid tumour
tumours showing histological features of neuroendocrine cells.
Carcinoma
a malignant tumour showing histological features of epithelium.
Carcinoma in-situ
an epithelial proliferation with the cytological characteristics of malignancy, but which
has not yet invaded beyond the epithelial basement membrane into underlying tissues.
benign and do not have the ability to metastasise.
Cardiac tamponade
compression of the heart by accumulation of fluid in the pericardial sac.
Caseous necrosis
grossly appears white, soft and cheese-like microscopically appears pink and granular with fragmented nuclei and no cellular detail.
seen in tuberculosis
Cerebral infarction
necrosis of cerebral tissue due to loss of blood supply.
Choledocholithiasis
calculi in the bile ducts.
Cholelithiasis
calculi in the gallbladder
Chronic bronchitis
persistent cough productive of sputum for at least 3 months in at least 2 consecutive years.
Histologically characterised by an increase in the Reid index (ratio of the thickness of the bronchial mucous glands to the thickness of the bronchial wall from the epithelium to the cartilage).
Chronic obstructive pulmonary disease (COPD)
a term that incorporates both emphysema and chronic
bronchitis, the features of which commonly overlap.
Cirrhosis
a state of abnormal liver anatomy where regenerating hepatocytes form nodules that are completely surrounded by fibrous bands (septa).
Clotting of blood
process of haemostasis after haemorrhage, or
solidification of blood in the vascular tree after death.
Coagulative necrosis
a pattern of necrosis seen in infarcts.
Microscopically, appears as “ghost cells”, that have lost nuclei and cytoplasmic detail, but the overall tissue
architecture is retained.
Congestion (vascular)
engorgement of a vascular bed with blood. Congested tissues appear grossly red
Consolidation
solidification of lung tissue, sometimes due to accumulation of inflammatory exudate within
the alveoli as a feature of bacterial pneumonia.
Cor pulmonale
isolated right ventricular failure arising as a result of pulmonary hypertension
Cribriform
growth pattern seen in carcinomas, where a group of tumour cells are perforated by round glandular spaces so as to resemble a sieve
Crohn’s disease
one of the two forms of chronic inflammatory bowel disease
Cryptogenic/idiopathic
of unknown cause
Cyst
an abnormal enclosed epithelial-lined sac that contains material secreted by the epithelium.
Cytokeratins
structural proteins present in epithelial cells.
Cytokine
small secreted proteins involved in cell signalling including in inflammation, immune responses
and haematopoiesis.
Cytology
the appearance or features of individual cells
Desmoplasia
fibrous tissue which forms in response to tissue invasion by a malignant tumour.
Differentiation
The process by which a cell becomes more specialised
Arterial dissection
the passage of blood into the wall of an artery via a tear in the intima, most commonly occurring in the thoracic aorta.
The blood creates a false passage in the outer media, which is split into two layers.
Diverticulitis
acute inflammation of a diverticulum
Diverticulum
localised out-pouching of mucosa through the wall of a hollow organ.
Dysplasia
disordered growth of cells or tissue
Ectopic
wrongly situated
Effusion
accumulation of fluid within a space or body cavity e.g. the pleural or pericardial cavity or joint
space.
Embolism
a mass of material carried within the vascular system.
Emphysema
destruction of lung tissue distal to the terminal bronchioles without fibrosis.
A disease of smokers.
Alpha—1—antitrypsin deficiency is a rare cause.
Empyema
accumulation of pus within the pleural cavity
Epithelioid
to resemble an epithelial cell
Erosion
a partial thickness breach of a mucosal layer.
Exudate
a fluid rich in protein and often cells, exuding from abnormally permeable vessels in response to
inflammation or injury.
Fat necrosis
death of fatty tissue occurring in response to enzymes released in acute inflammation, pancreatitis, or trauma.
bright yellow macroscopic appearance and is prone to calcification, producing chalky white deposits.
Fibrin
an insoluble protein, derived from fibrinogen, formed in the process of haemostasis andthrombosis
and present in acute inflammatory exudates.
Fibrinoid
resembling fibrin, deeply eosinophilic
Fibrinoid necrosis
necrosis of blood vessels (including glomerular vessels) associated with deposition of intensely eosinophilic proteinaceous material.
Fibrinous exudate
the fibrin rich exudate which forms on the serosal surface of inflamed organs.
dull, shaggy or stringy appearance
Fibroadenoma
a benign neoplasm of breast fibroepithelial tissue
Fibrosis
the formation of scar tissue in the processes of wound healing or chronic inflammation.
Fistula
an abnormal communication between two hollow organs, between a hollow organ and the skin,
between two blood vessels, or between a blood vessel and a hollow organ
Gangrene
necrosis of tissue with putrefaction (decomposition).
Giant cells
large multinucleated macrophages forming in response to certain stimuli, such as foreign material, insoluble material or pathogens.
Ghon complex
the lesions of primary pulmonary tuberculosis, consisting of an area of inflammation (granulomas and caseation) in the peripheral mid zone of the lung and enlarged, caseating hilar lymph nodes.
Ghon focus
the area of inflammation in the periphery of the lung, classically seen in primary pulmonary
tuberculosis.
Grading (of neoplastic lesions)
a histological assessment of the degree to which neoplastic cells resemble normal cells i.e. degree of differentiation.
Granulation tissue
the tissue of healing resulting in the formation of scar tissue that forms in response to inflammation, thrombosis and necrosis.
Granuloma
Histological description of a well-circumscribed collection of epithelioid macrophages +/- multinucleate giant cells
Granulomatous inflammation
specific type of chronic inflammation characterised by presence of epithelioid macrophages +/- multinucleate giant cells +/- necrosis.
form of cell—mediated immune response that develops in response to agents that are difficult or impossible to eradicate, such as foreign bodies and mycobacterium tuberculosis.
Haematemesis
vomiting of blood
Haematoma
a localised mass of blood outside the vascular tree.
Haemoptysis
coughing up of blood.
Haemorrhage
the abnormal presence of blood outside the vascular tree.
results from trauma to a vessel wall, or some form of
vessel wall abnormality leading to rupture.
Haemosiderin
a granular, brown substance containing iron, seen within macrophages, formed from the breakdown of haemoglobin in the tissue
Haemothorax
the presence of blood in the pleural cavity
Acute hepatitis
defined clinically as elevation of serum ALT (or AST) for
Chronic hepatitis
defined clinically as elevation of ALT (or AST)
for a period of greater than 6 months
defined pathologically as the presence of portal and periportal inflammation (interface hepatitis) and fibrosis.
steatohepatitis
hepatitis associated with fatty change (steatosis), hepatocellular ballooning degeneration (severe swelling) and, in severe cases, formation of Mallory bodies.
Hepatocellular adenoma
a benign neoplasm of hepatocytes
Hepatocellular carcinoma
a malignant neoplasm showing hepatocytic differentiation
Hyaline
a microscopic appearance described as glassy and eosinophilic.
Hydrocephalus
an increase in the amount of cerebrospinal fluid within the cranium, usually associated with dilatation of the ventricular system and commonly causing increased intracranial pressure.
Hyperchromasia
the property of being dark staining (“hyperchromatic”), usually used to describe the nuclei of malignant cells which contain excess nuclear DNA and so stain intensely with haematoxylin.
Hyperplasia
an adaptive change characterised by an increase in cell number.
Hypertrophy
an adaptive change characterised by an increase in cell size.
Hypoplasia
incomplete development or underdevelopment of an organ ortissue.
Hypoxia
deficiency of oxygen in tissues
Idiopathic
of unknown cause (also called cryptogenic).
Induration
hardening to palpation, caused by inflammation or infiltration by aneoplastic population.
Infarction
death of tissue due to reduction or loss of blood supply.
Acute Inflammation
the host response occurring in the first 24-48 hours after injury. There is vascular dilatation leading to increased blood flow, increased vascular permeability leading to exudation of protein-rich fluid, and the migration of neutrophils into the tissue leading to a cellular exudate.
Chronic Inflammation
the host response to a prolonged or persistent stimulus characterised by predominantly mononuclear inflammation (lymphocytes and plasma cells) and fibrosis.
Interface hepatitis
death of hepatocytes at the interface with connective tissue of the portal tracts, associated with lymphoplasmacytic inflammation.
pathological hallmark of chronic hepatitis but is not specific for it.
Ischaemia
reduction or loss of blood supply leading to deprivation of oxygen and nutrients. Leads to tissue necrosis if of sufficient duration.
Koilocyte
an abnormal squamous cell seen in the mid-upper epithelium with infection by HPV.
Typically has a clear halo around an irregular, raisin—like nucleus. May be binucleate.
Left shift
the appearance of immature neutrophils (myelocytes and metamyelocytes) in the peripheral blood.
Leukaemia
malignant neoplastic proliferation of haematolymphoid cells, mostly at a precursor stage.
Lipofuscin
an intracellular granular yellow-brown pigment occurring as a result of lysosomal breakdown of
cellular components related to ageing.
Liquefactive (necrosis)
the pattern of necrosis typical of cerebral infarction and also in association with abundant neutrophils with the formation of pus.
As a result of enzymatic digestion, the necrotic tissue
liquefies leading to the formation of a fluid—filled pace.
Lymphadenopathy
enlargement of lymph nodes
Lymphoma
a neoplasm of cells showing lymphoid differentiation
Malignant (neoplasm)
a neoplasm which infiltrates
Mesothelioma
a malignant tumour showing mesothelial differentiation.
Metaplasia
the replacement of one cell type by another in response to an environmental stress.
Metastasis
Growth of secondary malignant tumour at a site separate from the primary tumour from which it arose
Atypical mitosis
an abnormally configured mitotic figure
Monoclonal
tumour or cellular proliferation derived from a single cell.
Morphology
the form or structure of organs, tissues and cells.
Myeloma (multiple myeloma)
malignant tumour of plasma cells.
Myocardial infarction
death of cardiac myocytes due to reduction or loss of blood supply.
Necrosis
death of tissue.
Neoplasm
an abnormal proliferation of genetically altered cells which have escaped normal physiological control.
Oedema
abnormal accumulation of fluid in cells and tissues.
Oncocyte
epithelial cell with pink granular cytoplasm due to the presence of many mitochondria.
Organisation
ingrowth of granulation tissue to form scar tissue.
Papillary
forming finger—like projections, used to describe the arrangement of epithelial cells in
projections around fine vascular cores.
Papilloma
a benign neoplasm of squamous epithelial cells
Paraneoplastic syndrome
complications of malignant neoplasms that do not relate to the presence of the primary tumour, metastases or hormones that are normally produced by the tissue type of the tumour.
Pathogenesis
how a disease arises
Pathognomonic
feature so characteristic of a particular disease that it is sufficient to make the diagnosis.
Penetration
a pathological defect in the wall of a hollow viscus that extends into deeper tissues, typically relating to an ulcer.
Peptic ulcer
an ulcer, usually occurring in the stomach or duodenum, as a result of impaired mucosal
defence and injury from acid or pepsin (most commonly related to Helicobacter pylori infection or ingestion of
non—steroidal anti—inflammatory drugs).
Perforation
a pathological defect in the wall of a hollow viscus (typically caused by necrosis such as in
peptic ulcers, acute inflammation or malignancies) that extends through into another space.
Petechia
a pin-point haemorrhage resulting from injury to small vessels and is non blanching
Pleomorphism
a descriptive term referring to variation in
size and shape of cells and nuclei
Pneumoconiosis
lung disease caused by the inhalation of dusts, most often in an occupational setting
Pneumonia
inflammation of the lung, often restricted in common usage to infectious causes.
Polyclonal
cellular proliferation derived from multiplecells.
Polyp
a descriptive term referring to a discrete elevation of a mucosal surf
Pott’s disease
tuberculosis of the spine.
Pseudocyst
a fluid filled cavity that may form in acute pancreatitis.
Purpura
red or purple patches >3mm size on the skin caused by bleeding from small blood vessels.
Purulent
containing pus
Pus
inflammatory exudate accumulating in response to certain types of bacterial infection, composed of
necrotic cellular debris and neutrophil polymorphs both living and dead.
Pyogenic
pus forming
Regeneration
the replication of cells to replace those lost following injury
Repair
the process by which damaged or destroyed tissue is replaced by scar tissue, when resolution is not
possible, usually either because the injured cells are unable to divide or because the connective tissue
framework has been too severely disrupted.
Resolution
the return to normal structure and function of a tissue after injury. This requires that any injured cells can divide and that the connective tissue structure is not severely disrupted.
Sarcoma
a malignant tumour showing features of cells derived from mesenchymal tissues.
Sclerosis
induration or hardening, often due to deposition of connective tissue
Stage
the extent to which a tumour has progressed through its natural history, expressed in termsof
anatomical spread. Stage is assigned using the TNM (tumour, nodes, metastases) system
Steatosis (macrovesicular)
a form of reversible cell injury characterised by the accumulation of large triglyceride droplets in hepatocytes
Steatosis (microvesicular)
an uncommon pathological change which is sometimes fatal
Suppuration
production of pus
Teratoma
a neoplasm containing tissue from all three layers of the embryo; a form of germ cell tumour.
Thrombus
a clotted mass of blood that forms within the cardiovascular system, i.e. within a blood vessel or the heart, during life.
Transudate
extracellular fluid with low protein and cell content, arising from increased capillary hydrostatic pressure.
Tubercle
a small nodule caused by infection with Mycobacterium tuberculosis. Histologically, tuberclesare
granulomas usually containing a central area of caseous necrosis approximately 2mm in diameter.Tubercles fuse together to produce progressively larger areas of necrotising granulomatous inflammation.
Tuberculosis
chronic bacterial infection by the organism Mycobacterium tuberculosis.
Ulcer
a full thickness breach of a mucosal surface or of the epidermis.
Ulcerative colitis
one of the two forms of idiopathic chronic inflammatory bowel disease
characterised by colonic mucosal inflammation extending proximally in a continuous fashion from an involved rectum.
Varix
a dilated vein.
Villous
finger-like projections, typically used to describe the arrangement of epithelial cells in projections around fine vascular cores.
What are the 4 types of cellular adaptation?
hypertrophy (increased cell size)
hyperplasia (increased cell number)
metaplasia (the replacement of one cell type by another)
atrophy (reduction in size of cells, tissues or
organs).
What are the two most common forms of amyloid?
1) AL amyloid composed of immunoglobulin light chains produced by plasma cell neoplasms such as multiple myeloma and
2) AA amyloid composed of serum amyloid—associated protein produced in increased amounts by the liver in chronic inflammatory conditions such as rheumatoid arthritis
Why does both the pulmonary lymphatics and lymph nodes appear black to the naked eye?
Collection of carbon in macrophages of city dwellers or coal miners
Dilated veins in the anorectal region
haemorrhoids.
Causes of bronchiectasis
Bronchial obstruction by tumour, tuberculosis or mucus in cystic fibrosis causing recurrent necrotising
infections.
Consequences of cardiac tamponade
impairs
cardiac filling and thus cardiac output
dystrophic Calcification
occurring in necrotic, inflamed or otherwise damaged tissue
metastatic calficiation
secondary calcification to hypercalcaemia
common cause of cerebral infarction
thromboembolism
What type of necrosis do cerebral infarcts undergo?
liquefactive
What is a nonspecific feature of end stage liver disease?
cirrhosis
What are some causes of cirrhosis?
alcohol viral hepatitis B and C non-alcoholic fatty liver disease autoimmune hepatitis primary biliary cirrhosis primary sclerosing cholangitis haemochromatosis Wilson’s disease
What is the most common part of the GI tract that Crohn’s disease affect?
ileum and the colon
hallmark pathological features of Crohn’s disease?
transmural inflammation
deep ulcers with a fissuring quality
formation of granulomas
Where are diverticulum most commonly found?
sigmoid colon
What are the components of granulation tissue?
capillaries, fibroblasts, varying amounts of collagen over time, and inflammatory cells.
