Pathology of Gastrointestinal Cancers Flashcards
What is meant by an adenoma?
Benign neoplastic growth e.g a dysplastic polyp in the colon / rectum.
What are the key differences between benign and malignant neoplasms?
Malignant neoplams are infiltrating and invasive to tissue and metastasise to other sites.
Benign neoplasms are localised and encapsulated.
Metastisis
Secondary deposit of cancer away from the primary cancer.
Dissemination (metastasis) occurs through what 4 processes?
- Haematogenous spread - venous to liver/lungs.
- Lymphatic spread to regional lymph nodes.
- Seeding of body cavities e.g peritoneal cavity.
- Mechanical spread e.g needle biopsy tract. (Iatrogenic).
Which of well differentiated and poorly differentiated neoplasms have the worse prognosis?
Poorly differentiated malignant neoplasms have the worst prognosis.
What microscopic features indicate malignancy?
- Increased Nuclear:Cytoplasmic ratio as the nucleus enlarges.
- Pleomorphism - lot’s of different forms.
- Hyperchromatic (dark) nuclei
- Mitoses
- Loss of polarity - no clear organisation
Carcinoma refers to cancer of the
epithelium
Melanoma refers to cancer of the
Melanocytes
Sarcoma refers to cancer of the
Mesenchymal cells / germ cell tumour
What is the normal epithelial lining of the oesophagus?
Squamous epithelium
What type of cancer normally forms in the oesophagus? (excluding barretts)
Squamous cell carcinoma
What changes to epithelium occur in Barrett’s oesophagus?
Squamous epithelium is replaced by glandular epithelium (columnar metaplasia).
Risk of malignancy - formation of an adenocarcinoma.
Why does metaplasia of squamous to columnar epithelium occur in Barrett’s oesophagus?
The squamous epithelium is unable to deal with the acidic conditions resulting from GORD, where as the columnar epithelium can - hence you get metaplasia to columnar epithelium.
Staging of oesophageal dyplasia
What epithelium lines the stomach?
Simple columnar - glandular epithelium
What are the risk factors of gastric cancer?
Smoking
Diet
H.pylori infection
What type of malignancy may be seen in the stomach?
Adenocarcinoma
Metaplasia dysplasia carcinoma sequence
What are the two main types of gastric adenocarcinoma?
- what’s the prognosis for each?
Intestinal type - low grade, localised growth
Diffuse type - infiltrative - consists of poorly cohesive maligant cells that are invasive.
Signet ring cell carcinoma = diffuse type
Signet ring cell carcinoma
Signet ring cell carcinoma (SRCC) is a rare form of highly malignant adenocarcinoma that produces mucin.
Histology of gastric adenocarcinoma
Histology of signet ring cell carcinoma
What are the different types of gastric tumours?
Gastric adenocarcinoma
Neuroendocrine tumours
Gastrointestinal stromal tumours
Lymphoma B-cell tumours
H.pylori can give you what two types of stomach cancer?
Gastric adenocarcinoma
Lymphoma
What do gastric neuroendocrine tumours secrete?
Gastric neuroendocrine tumours secrete gastrin.
What is the histology seen here?
What cause gastric neuroendocrine tumours to form?
Arise in stomach on a background of hypergastrinaemia (atrophic gastritis or gastrin-producing neoplasm) or occur sporadically.
Gastrinoma – duodenum or pancreas.
Summary of gastrointestinal stromal tumours.
What can been seen here?
What is the most common cause of small bowel tumours?
Metastasis
What are the different types of small bowel tumours?
- Neuroendocrine tumours most common neoplasm.
- GISTs
- Lymphoma
- Small bowel adenocarcinoma
What are the risk factors of small bowel adenocarcinoma?
Familial Adenomatous Polyposis (FAP), Crohn’s disease, coeliac disease.
What is the most common type of tumour seen in the appendix?
Neuroendocrine tumour
How is the risk of progression of an adenoma in the colon classified?
Risk of progression to invasive adenocarcinoma is related to the number, size, villous architecture, and grade of dysplasia.
Note: average progression from adenoma to adenocarcinoma is around 10 years.
Histology of colorectal adenoma’s
Tubular
Villous
Low grade
High grade
What is being shown here in this histology slide?
Name the condition shown?
What is the treatment?
Familial Adenomatous Polyposis
Treatment is Colectomy
How are tumour staged?
TNM Classification
T - extent of primary tumour
N - lymph node involvement
M - Distant metastases
Tumour Staging (T)
Lymph Node Staging (N)
Metastasis staging (M)
What can be seen in this histology?
What can be seen in this histology?
Peutz Jeghers Syndrome
Peutz-Jeghers syndrome is characterized by the development of noncancerous growths called hamartomatous polyps in the gastrointestinal tract (particularly the stomach and intestines) and a greatly increased risk of developing certain types of cancer.
What does lynch syndrome lead to?
Lynch syndrome which is characterised by aggressive right sided colonic malignancy and endometrial cancer is caused by microsatellite instability of DNA repair genes.
