• Replacement of one cell type with another
• Examples:
• Smoking: Columnar => Squamous
• Barrett's oesophagus: Squamous => Columnar
• Cervix: Columnar => Squamous

Cancer definition

1. Invasive growth
2. Metastatic potential

Epithelial cancers

• Most common type
• All called carcinoma
• Subtypes:
• Squamous cell carcinoma
• Keratin production
• Intracellular bridges
• Adenocarcinoma
• Acini (glands)
• Mucin production

Dukes staging

• Dukes' A
• Invasion into but not through the bowel wall - i.e. Not below muscularis propria
  
• 90% 5-y survival
• Dukes' B
• Invasion through the bowel wall (i.e. into or through subserosa) but not involving lymph nodes
• 70% 5-y survival
• Dukes' C
• Any primary tumour invasion with involvement of lymph nodes
• 30% 5-y survival
• Dukes' D
• Widespread metastases

Dysplasia/CIS

• Presence of abnormal cells
• But ABOVE basement membrane
• => No metastatic potential, as no access to blood or lymph
• => NOT cancer (fails criteria 2)

Breast lumps

• Fibrocystic change / fibroadenosis
• Common (50% of women)
• Usually most obvious in the week before period
• Quickly goes when period starts
• More common in women aged 30-50
• Fibroadenoma
• Benign
• Common in women <40
• Result of excess growth of the glands and connective tissue in the breasts
• Round, firm, rubbery, mobile lumps
• Not usually painful
• Cyst
• More common in women approaching menopause
• Usually oval or round lumps that are smooth and firm
• Slightly mobile
• Common for them to appear within two weeks prior to period and then resolve soon after the period
• Breast abscess
  
• Fat necrosis
• From injury or trauma
  
• Usually self-limiting
• Lipoma
• Benign
• Breast cancer

Breast cancer

• Types
• Invasive ductal carcinoma (75%)
  
• Invasive lobular carcinoma (10%)
• DCIS
• NOT cancer - Still in the duct
• Usually no lump; Asymptomatic
• Causes calcification, which is detected by screening
• Receptors
• ER +ve
• 80%
• Normally less aggressive
• Respond to hormone therapy
  
• HER2 +ve
• 15%
• Normally more aggressive
  
• But respond to herceptin

Eaton–Lambert syndrome

• Autoimmune disorder that is characterised by muscle weakness of the limbs
• Antibodies vs presynaptic voltage-gated Ca channels in NMJ
  
• Paraneoplastic phenomenon
•  60% have an underlying malignancy, most commonly small cell lung cancer
• Direct treatment of the cancer often relieves the symptoms
• Signs and symptoms
• Weakness typically involves the legs and arms
• Primarily proximal muscles
  
• Leg involvement is more striking than in myasthenia gravis
• Physical exercise and high temperatures can worsen the symptoms
• Three quarters have disruption of the autonomic nervous system
• Lambert's sign
• Strength improves further with repeated testing, e.g. improvement of power on repeated hand grip
• At rest, reflexes are typically reduced; with muscle use, reflex strength increases

Notes

• Hyperplasia vs Neoplasia
• One has a stimulus, one doesn't
• Viscus = Hollow organ with muscular wall
• "Clinically benign" can mean two things
• Dysplasia/CIS (which is a ticking bomb and must be sorted)
• Benign tumour (which is actually benign)
• You want to be ER+ve, HER2 -ve
• Paraneoplastic = Anything other than mass effect
• In colon cancer, invasion (i.e. cancer) corresponds to invasion through the muscularis mucosa (i.e. into the submucosa)
• EVEN THOUGH the basement membrane is underneath the epithelial layer