The Role of the Pathologist in Patient Care Flashcards
What is pathology?
Pathology is the study of disease. The word is derived from ‘pathos’ - suffering and ‘logos’ - study (Greek).
What is the difference between a histopathologist and a cytopathologist?
Histology is the study of tissue and histopathologists study diseases in tissue biopsies, usually using a light microscope. Cytology is the study of cells and cytopathologists study cells from fluids scrapings/brushings or from fine needle aspirates.
How do you distinguish a benign cell from a malignant cell?
Malignant cells have high nuclear to cytoplasmic ratios, irregular nuclear membranes and an irregular distribution of chromatin within the nucleus. Benign cells have low nuclear to cytoplasmic ratios, smooth nuclear membranes and evenly distributed chromatin.
Into what medium do you place a biopsy for histopathological assessment?
Tissue biopsies are placed in formalin (a mixture of formaldehyde and saline).
What happens to tissue if you do not do place it in formalin?
The tissue will rot and will not be able to be examined. Formalin crosslinks proteins within the tissue stopping its breakdown.
What is the stain used most commonly in histopathology?
H+E (Haematoxylin and Eosin). Haematoxylin stains nuclei blue and eosin stains cytoplasm pink.
Which cell produces collagen which makes some tumours feel hard on palpation?
Fibroblasts produce collagen around tumours. Collagen is a protein which makes tumours and scar tissue hard to palpation.
What is the difference between a transudate and an exudate?
A transudate is a fluid (eg. within the pleural cavity) which is low in protein and an example of a transudate is a pleural effusion caused by heart failure. An exudate is a fluid which is high in protein and an example of an exudate is an effusion caused by infection or malignancy.
What is an adenocarcinoma and how can we tell if a tumour is an adenocarcinoma?
An adenocarcinoma is a malignant epithelial tumour showing gland formation (glandular differentiation). Normal glands produce mucin and malignant glands (from an adenocarcinoma) will also produce mucin.
What is immunohistochemistry?
Immunohistochemistry is the application of labelled antibodies to tissue slides in order to detect the presence of certain antigens of interest within the nucleus, cytoplasm or membranes of cells. This technique is used to tell pathologists where a tumour has come from or the cell type which is present or what receptors a tumour is expressing.
