Intro to Benign and Malignant Disease

Question 1

Define:

• hypertrophy:
• hyperplasia:
• atrophy:
• hypoplasia:

Answer 1

• hypertrophy: an increase in cell size, physiological or pathological, muscle (cardiac or skeletal)
• hyperplasia: an increase in cell number, physiological or pathological, seen in hormonally sensitive organs (endometrium, breast, thyroid)
• atrophy: reduction in cell size by loss of cell substance, physiological (thyroglossal duct) and pathological (ageing, lack of use/stimulation)
• hypoplasia: reduced size of an organ that never fully developed to normal size (developmental defect)

Question 2

Define:

• metaplasia:

Which of the following are potentially reversible?

Hypertrophy, hyperplasia, atrophy, hypoplasia, metaplasia?

Answer 2

• metaplasia: reversible change in which one adult cell type is replaced by another adult cell type, can be part of an adaptive response to stress, reprogramming of stem cells

E.g. barretts oesophagus, bronchus, salivary ducts

With the exception of hypoplasia, all other changes are potentially reversible.

Question 3

What is dysplasia?

What are the different degrees of dysplasia?

What is the key difference between dysplasia and cancer?

Answer 3

Dysplasia ‘‘abnormal growth’’

• a pre-malignant process
• can be identified in many tissues, particularly good in epithelia e.g. squamous (mouth) or glandular

Degrees of dysplasia:

• mild
• moderate
• severe (carcinoma in situ)

The more severe forms have a more significant risk of progressing to invasive malignancy

Cells show abnormal features that are also seen in cancer cells, they are NOT invasive - the abnormal cells remain within the epithelium

Question 4

What is a neoplasia?

Answer 4

Neoplasia ‘‘new growth’’

• results from aberration of the normal mechanisms that control cell number: cell production by cell division, cell loss by apoptosis

Question 5

How can tumours be classified?

Answer 5

• behaviour: benign or malignant
• histogenesis: according to cell type they resemble

Question 6

What are the features of a benign tumour with regards to:

• growth pattern:
• growth rate:
• clinical effects:
• treatment:

What is the most common benign salivary tumour?

• histology:
• nuclei:
• mitoses:

Answer 6

• growth pattern: expand and remain localised, typically well circumscribed, often encapsulated
• growth rate: slower
• clinical effects: local pressure effects, hormone secretion
• treatment: local excision

Pleomorphic adenoma, most commonly affects parotid gland

• histology: resembles tissue of origin
• nuclei: small, regular, uniform
• mitoses: few, normal

Question 7

What are the features of a malignant tumour with regards to:

• growth pattern:
• growth rate:
• clinical effects:
• treatment:
• histology:
• nuclei:
• mitoses:

What is a pleomorphic adenoma which becomes malignant named?

Answer 7

• growth pattern: infiltrate locally, metastasize
• growth rate: faster
• clinical effects: local pressure and destruction, inappropriate hormone secretion, distant metastases
• treatment: excision with or w/out additional therapy
• histology: variable, many differ from tissue of origin
• nuclei: larger, pleomorphic
• mitoses: increased, often numerous, abnormal forms

Pleomorphic adenoma –> carcinoma ex pleomorphic adenoma

Question 8

Why does tumour type matter?

Answer 8

• different tumour types behave in different ways
• different benign tumours can behave differently
• not all malignant tumours are equally malignant

Question 9

What is a prognosis?

What is cancer prognosis dependent upon?

Answer 9

Prognosis: prediction of the probable course and outcome of disease, appropriate treatment and estimate survival

Cancer prognosis:

• tumour type/grade/stage
• other parameters: patient/tumour

Question 10

What is tumour grade?

What is tumour staging?

Answer 10

Tumour grade:

• a histological assessment, how well differentiated the tumour cells are
• well differentiated tumours tend to have a better prognosis

Tumour staging: anatomical extent of disease

• clinical, radiological and pathological findings

0 major determinant of appropriate treatment and prognosis

Question 11

What does TNM stand for when staging tumours?

What is a low stage tumour?

High stage tumour with poor prognosis?

Answer 11

T - extent of primary tumour (greatest diameter of tumour, structures invaded)

N - absence or presence and extent of regional lymph node metastasis

M - describes the absence or presence of distant metastasis

Low stage: T1N0M0

High stage: T4N2M1