Module 3 Part 1 - Neoplasia Flashcards
Neoplasm
An abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the surrounding tissues and persists in the same excessive manner after cessation of the stimuli
Dysplasia
The presence of abnormal cells within a tissue or organ
May be neoplastic and pre-malignant
May regress
e.g. Colon adenoma
Benign and Malignant Suffixes
Benign finishes in -oma e.g. fibroma
Malignant ends in -sarcoma e.g. fibrosarcoma
Tissue of Origin Prefixes
Fibrous - firbo- Bone - osteo- Cartilage - chondro- Adipose - lipo Smooth muscle - leiomyo Skeletal muscle - rhabdomyo
What is Differentiation?
The extent to which tumour cells resemble normal cells in structure and/or function
Benign tumours are well differentiated, and are only recognised as tumours because of:
- formation of an abnormal mass
- demonstration of a specific genetic abnormality
- production of a hormone or product with harmful effects
Malignant tumours are classified as well, moderately, poorly differentiated, or undifferentiated/anaplastic
Pleomorphism
Variation in size and shape of the cell or nucleus
This increases with loss of differentiation
Nuclear Atypia
Neoplasia is a genetic disease that is reflected in changes in the nuclei of neoplastic cells
Changes include:
- hyperchromasia (dark nuclei due to increased amount of chromatin)
- change in nuclear cytoplasmic ratio (usually increase in size of nucleus in relation to cytoplasm)
- mitotic activity
- loss of polarity (some cells show polarity of nucleus e.g. glandular epithelial cells), in neoplasia cells may lose polarity entirely
Benign Neoplasms
Slow growing
Locally confined
Cause symptoms by mass effect
- e.g. compression of adjacent structures
May be asymptomatic until very large in size
May cause significant problems even when small
Cured by surgical excision
Unlikely to cause death except where mass effects or hormone production affect viral functions
Malignant Neoplasms
Tumour isn’t confined
Capable of invasion of adjacent organs/structures
Capable of distant metastasis
Only curable if completely excised before spread and/or sensitive to appropriate treatment
Cytologically more atypical than benign
May be more mitotically active than benign tumours, especially atypical mitoses
Spread of Malignant Tumours
Direct Invasion
Lymphatic invasion - to lymph nodes
Vascular invasion - to other organs in the vascular pathway
Transcoelomic spread
Grade and Stage
Grade
- measure of how aggressively a tumour behaves
- generally corresponds with differentiation and mitotic activity
Stage
- how far the tumour has advanced at the time of diagnosis
- combination of the features of the tumour (size, extent of invasion), nodal involvement and metastasis
What is Anaplasia?
The complete lack of differentiation within a tumor
Karyorrhexis, Karyolysis and Karyopyknosis
All part of necrosis
Karyopyknosis
- nuclear shrinkage
- DNA condenses into shrunken basophilic mass
- nucleus is heavily stained with haematoxylin (dark pink)
Karyorrhexis
- nuclear fragmentation
- pyknotic nuclei membrane ruptures and nucleus undergoes fragmentation
Karyolysis
- nuclear fading
- chromatin dissolution due to action of DNases and RNases
- complete nuclear breakdown
Stages of Cancer
Stage 0
- describes cancer in situ
- located at the place the cancer started and hasn’t spread at all
- easy to cure as the whole tumor can be removed via excision
Stage 1
- small cancer that has not grown deeply into neighbouring tissue
- also hasn’t spread or metastised
Stage 2
- cancer has grown from stage 1 but still hasn’t spread
Stage 3
- the cancer is larger and may have spread to the surrounding tissues and/or the lymph nodes
Stage 4
- the cancer has spread to another organ
- a.k.a secondary or metastatic cancer
Difference Between a Carcinoma and a Sarcoma
Carcinoma - neoplasm arising in epithelial tissue e.g. adenocarcinoma, squamous cell carcinoma
Sarcoma - neoplasm arising in mesenchymal tissue e.g. fibrosarcoma, liposarcoma
