Neoplasia IV Flashcards
4 things a pathologist must find out about a cancer?
Can it be surgically removed?
What is it?
How far has it spread? - depends on type of tumour and anatomical site
How bad is it? How malignant is it behaving? - different to spread
Normal histology?
Nature likes organisation, smooth edges, round things, symmetry and also uniformity (homogenous)
Most growing lesions stimulate a response by surrounding tissue and it is fenced off with a capsule (ENCAPSULATED) - forming a capsule takes time and indicates that the lesion is slow-growing (slow-growing lesions are usually benign)
Malignant lesions characteristics?
Look bad
Do not look normal:
Pleomorphism - many shapes and sizes
Hyperchromasia - many different colours (some benign tumours can have this)
Mitoses - rapid proliferation/abnormal mitosis is disorganised in malignancy
Irregular
Infiltrative (edge is not smooth)
Destructive (grows in and destroys tissues)
Necrosis - in centre of tumour
Not encapsulated
Heterogenous appearance?
Different areas due to, e.g: haemorrhage and necrosis (lack of blood supply to tumour)
Histopathology of benign structures?
Nature likes organisation, etc
Regularity - nuclei look like each other and are the same colour
What is the N:C ratio?
Nucleus : Cytoplasm ratio
Low ratio is a benign feature
High ratio is a feature of malignant tumours
What is differentiation?
All cells originate from a stem cell and receive various signals to mature into a specific cell type with a specific function - cells differentiate/specialise
Well differentiate - cells appear as they should
Poorly differentiated - difficult to tell what the cell of origin is (can be characteristic of cancer)
Taxonomy of tumours?
Big groups: Epithelial Mesenchymal - connective tissue Haematopoietic - wbcs, etc Others - melanocytic, brain (glial)
Types of epithelial cancer?
Epithelium - carcinomas
Glandular - adenoma (benign) vs carcinoma (malignant)
Squamous - papilloma (finger-like) vs SCC (Squamous Cell Carcinoma)
Bladder - Transitional Cell Carcinoma (TCC), some times called urothelial cell carcinoma
Benign and malignant name endings?
Benign -oma
Malignant -cinoma
What is a mesenchyme?
Connective tissue, like bone, cartilage, peripheral nerves, fat, fibrous tissue, smooth muscle, skeletal muscle and others
Malignant lesions of connective tissue are known as?
SARCOMAS
Tumours of fat tissue?
Benign tumours are common - lipoma (usually subcutaneous)
Malignant - liposarcoma (rare, and tend to be in deep, soft tissue, retroperitoneal and testicular)
Tumours of bone?
Benign - osteoma
Malignant - osteosarcoma. Rare and tend be in children with long bones
Tumours of cartilage?
Benign - enchondroma (lots of)
Malignant - chondrosarcoma
“Chondro”
Tumours of striated muscle?
Rhabdomyoma - rare and tend to be in children
Rhabdomyosarcoma - rare and tend to be in eye, bile duct, gynae tract and some other areas
“Rhabdo” - derived from “striated”
Tumours of smooth muscle?
Benign - leiomyoma (one of the most common tumours in the body - common in uterus, etc)
Leimyosarcoma - very uncommon
Tumours of nerves?
Benign - neurofibroma, schwannoma (benign tumour of schwann cells)
Malignant - malignant peripheral nerve sheath tumour
Tumours of blood vessels?
Benign - haemangioma, etc
Malignant - angiosarcoma, Kaposi’s sarcoma (often seen in AIDs but is not caused by it; caused by an infection and is susceptible to Herpes virus)
What is Ewing’s sarcoma?
Rare disease in which cancer cells are found in the bone or in soft tissue
What is synovial sarcoma?
Rare form of cancer which usually occurs near to the joints of the arm, neck or leg. It is one of the soft tissue sarcomas
What is a fibrosarcoma?
Sarcoma in which the predominant cell type is a malignant fibroblast.
Tumours in CNS?
Gliomas - different group that range from benign version of a tumour to malignant version
Meaning of melanocytic?
Freckle - ephelis
Mole - naevus
Malignant - melanoma (exception to benign ending with -oma)
Blood tumours?
ALWAYS MALIGNANT as already systemic, e.g: leukaemias and lymphomas
Staging?
TNM - Tumour Node Metastasis
Often depends on site
Stage does not equal progression:
Can have a well differentiated tumour that has grown slowly but has been there for a long time - will have a high stage
Could have an aggressive, rapidly-growing cancer that is caught early - will have a low stage
Grading?
Give an indication of what cells are actually like
Can use concept of differentiation:
Well differentiated = low grade
Poorly differentiated = high grade
What is needed to characterise a tumour?
Both stage and grade
