Common pathology definitions Flashcards
What is an abscess?
-collection of pus
-surrounded by granulation or fibrous tissue
What is pus?
Pus is a collection of neutrophils, together with dead or dying micro-organism
What is a cyst, and how is this different from a pseudocyst?
-abnormal membranous sac containing a gaseous, liquid, or semisolid substance.
-This differs from a pseudocyst in that a pseudocyst lacks epithelial or endothelial cells.
What is a sinus?
A sinus is a blind-ended track lined by granulation tissue, which normally connects an
abscess to the skin
What is a stoma? How can they be classified?
A stoma is a surgical opening into a hollow viscus. It can be classified by anatomical site
(colostomy, ileostomy, urostomy, tracheostomy, gastrostomy), temporary vs permanent, or
the number of openings (loop vs end).
What is an aneurysm?
An aneurysm is an abnormal, permanent, localised dilatation of a blood vessel to >1.5x its
normal diameter
What are diverticula?
A diverticulum is an abnormal outpouching of a hollow viscus into the surrounding tissues
What are the differences between a clot, a thrombus and an embolus?
A thrombus is defined as solid material formed from the constituents of blood in flowing
blood.
When formed in stationary blood this is termed a clot.
An embolus is defined as an abnormal mass of undissolved material that is carried in the
bloodstream from one place to another.
What is necrosis?
Necrosis is defined as abnormal tissue death during life
What are hypersensitivity reactions?
A hypersensitivity reaction represents an exaggerated response of the host’s immune system
to a particular stimulus
What is a tumour marker?
A tumour marker is a substance which can found in the circulation of a patient with neoplasia
What is a polyp?
A polyp is a pedunculated mass of tissue arising from an epithelial surface
What is a neoplasm?
A neoplasm is an abnormal growth of tissue which displays:
Uncoordinated growth
Growth which exceeds that of the normal tissue
Growth which continues despite removal of the original stimulus
What is hyperplasia?
Hyperplasia is an increase in the size of an organ or tissue through an increase in the
NUMBER of cells. The cells are of normal size and morphology
What is hypertrophy?
Hypertrophy is an increase in the size of an organ or tissue through an increase in the SIZE of
the cells. The number of cells remains the same, as does the morphology.
What is a hamartoma?
A hamartoma is a tumour-like malformation composed of a disorganised arrangement of
different amounts of tissue normally found at that site. It grows under normal growth
controls.
What is metaplasia?
Metaplasia is a REVERSIBLE replacement of one fully differentiated cell type with another
differentiated cell type
What is dysplasia?
Dysplasia is disordered cellular development characterised by increased mitosis and
pleomorphism but WITHOUT the ability to invade the basement membrane and metastasise
Note: Severe dysplasia = carcinoma-in-situ
What are carcinomas and sarcomas?
A carcinoma is a malignant tumour of epithelial cells
A sarcoma is a malignant tumour of connective tissue
What is a metastasis?
A metastasis is the survival and growth of cells that have migrated from a malignant tumour
to a site distant from the primary tumour
What is a fistula?
A fistula is an abnormal communication between two epithelial surfaces (or endothelial
surfaces e.g AV fistula).
