13.02.14 Pathology teaching - neoplasia

Metaplasia

• • 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