Tumour Typing Grading and Staging

Tumour typing grading and staging

 What these are mean and what the benefits from its

Typing, grading and staging are important for

Planning of treatment

Type and degree of surgical excision

Consideration of pre-operative radiotherapy or chemotherapy to downsize

To provide accurate prognostic information

For the patient

For the physician

To provide accurate comparison between outcome in different patient

Comparisons between treatments

Comparisons between centres

Comparison of features in benign vs malignant

Benign neoplasms

• Expansile, usually slow growing

• Don not metastasise

• Low mitotic rate, little pleomorphism

• Normal chromosome numbers

• Necrosis and haemorrhage unusual

• More likely to be polypoid or papillary NB not all

Malignant neoplasms

• Infiltrative, irregular or fast growth rate

• May metastasise

• Pleomorphic, frequent mitotic figures

• Abnormal chromosome numbers

• Necrosis and haemorrhage may occur

• May be fungating or ulcerated
Tumour typing

the first piece of relevant information is the type of tumour. Tumours may be identified by similarity of their cells to the tissue of origin, if they remain well differentiated. With a poorly
differentiated metastatic deposit it may be impossible to identify its source. neoplasm are named according to whether they arise from epithelium or stroma
Epithelial neoplasms as .Adenoma: benign epithelial neoplasm forming a glandular pattern or arising from a gland.but not necessarily forming a glandular pattern
Papilloma: benign epithelial neoplasm protruding from a surface which produces
 finger-like fronds made up of connective tissue processes covered by epithelial cells

.Cystadenoma: benign epithelial neoplasm arising from duct or gland epithelium with secrtion and distension of the lumen due to lack of drainage

-Carcinoma: a malignant epithelial neoplasm
mesnechymal neoplasms

these are named according to cell type

oma: if benign eg lipoma

sarcoma: if malignant eg osteosarcoma
 
Tumour grading

This is an assessment of the degree of differentiation of a tumour and corresponds to the

aggressive behaviour of the tumour. Tumours are graded as

• Well differentiated

• Moderately differentiated

• Poorly/undifferentiated/anaplastic

Many different grading systems exist for different tumours that take into consideration growth patterns as well as differentiation status eg Gleason grade for prostate cancer

Differentiation refers to the degree to which neoplastic cells resemble their tissue of origin 

Features of poor differentiation are

• Increased nuclear pleomorphism

• Atypical mitoses

• Hyperchromatic nuclei

• Increased nuclear to cytoplasmic size ratio

• Giant cells may be present

Tumour grading is important for prediction of tumour behaviour and prognosis. In general the less differentiated the tumour, the more aggressive its biological behaviour

Tumour staging

 This refers to the size and spread of the neoplasm as assessed by clinician, pathologist or sed for decisions on management and prognosis

Examples for tumour staging

Dukes' classification for colorectal carcinoma
Clark's classification for malignant melanoma
TNM tumour, node metastasis system

staging often requires extensive investigations of the sites most likely to be involved in disease and is  aimed at assessing degree of tumour spread to regional nodes and distant site

.Blood tests eg LFTs, tumour markers
Cytology or biopsy for histology
 Chest X-ray or CT
Abdominalinal USS or CT
MRI isotope bone scanning
Position emission topography PET
Diagnostic or staging laparoscopy
Full staging may not be possible until after surgery to resect the tumour when regional lymph nodes can be inspected histologically for tumour deposits
failure to identify distant metastasis at the time of staging does not necessarily
mean that the patient is free from all tumour cells after resection of the primary. tumour cells continue to be present in the circulation until the primary is removed there may be tiny, as yet undetectable, metastatic deposits in other organs or lymph nods

TNM classification

The TMN classification was first developed by the American Joint Committee on Cancer
 staging and Result Reporting and has now been modified for systems for most solid breast, colon, thyroid.

The TNM staging system

T = primary tumour
  

 .To =  no primary tumour

Tis= in situ primary tumour

Tx = unknown primary tumour T1-4 Sizes of primary tumour

N = nodal metastasis

No No nodes

N1 Few node or nodes

 
N2-3 Relates to number, fixity, or distant lymph node group involvement

M = distant metastasis

Mo No metastasis

M1 Distant metastasis present

tags:tumour,grading,staging,typing