Lymphatic System and Venous Drainage

Intercostal Veins

• Drain into the azygos system and communicate with the valveless vertebral venous plexus (Batson's)
• This communication could explain the tendency of breast cancer deposits to affect the axial skeleton and central nervous system

Lymphatic Drainage

• Lymph vessels follow the course of blood vessels
• Six axillary lymph node groups:
  • Axillary nodes (lateral)
  • Anteromedial (pectoral; external mammary)
  • Posterior (subscapular) group
  • Central group
  • Apical group (subclavicular)
  • Interpectoral (Rotter)

Axillary Lymph Nodes

• Divided into three levels by the pectoralis minor muscle for prognosis after radical or modified radical mastectomy
  • Level I nodes: located low in the axilla, lateral or below the lower border of the pectoralis muscle
  • Level II nodes: located superficial or deep to the pectoralis minor muscle
  • Level III nodes: located medial or above the muscle in the apex of the axilla

Physiology of the Breast

• Hormonal control: breast development and function are initiated by estrogen, progesterone, and prolactin
• Physiological changes occur at puberty, during menstruation, pregnancy, lactation, and after menopause

Congenital Anomalies

• Anomalies of the nipple
• Anomalies of the breast
• Accessory breasts (polymastia)
• Accessory nipples (polythelia)
• Inverted nipple
• Enlarged breasts
• Amastia
• Accessory axillary breast

Diseases of the Male Breast

• Gynecomastia
• Male breast cancer

Infectious and Inflammatory Disorders of the Breast

• Acute lactational mastitis and breast abscess
• Non-lactational mastitis
• Chronic inflammatory conditions of the breast
• Mammary duct ectasia (plasma cell mastitis)
• Chronic pyogenic breast abscess
• Hidradenitis suppurativa
• Tuberculosis of the breast
• Mondor's disease

ANDI Syndrome

• Fibrocystic disease of the breast, a spectrum of breast conditions that ranges from normal to disorder to disease
• Aberrations of Normal Development and Involution (ANDI)
• Three stages: early reproductive years (15-25 years), later reproductive years (25-40 years), and involution (35-55 years)
• Pathological types: adenosis, epitheliosis, fibrosis, cyst formation

Cysts of the Breast

• Acinar cysts
• Retention cysts
• Galactocele (milk cyst)
• Intra-cystic papilliferous carcinoma
• Interacinar cysts

Nipple Discharge

• Causes: duct ectasia, fibrocystic disease, duct papilloma, duct carcinoma, contraceptive pills, hyperprolactinaemia

Diagnosis

• History and examination should provide information on:
  • Nature of discharge
  • Association with a mass
  • Unilateral or bilateral
  • Single duct or multiple duct discharge
  • Use of contraceptive pills
• Investigations:
  • Test for occult blood in the discharge
  • Cytology of the discharge for exfoliated cancer cells
  • Soft tissue mammography
  • Duct galactography
  • Serum prolactin estimation in suspected cases of galactorrhoea

Treatment

• A palpable mass should be excised for histology and treated accordingly
• A single duct bloody discharge calls for excision of this duct by microdochectomy
• Discharge from multiple ducts with no palpable or mammographic mass is initially treated conservatively by observation
• Rarely, the discharge is persistent and troublesome, where it is surgically treated by excision of the major ducts

Breast Neoplasms

• Classification and benign tumours:
  • Duct papilloma
  • Fibroadenoma
  • Cystosarcoma phylloides

Carcinoma of the Breast

• Aetiology:
  • Risk factors
  • Genetic factors (BRAC1 & BRACA2)
  • Endocrinal factors (hormonal)
  • Precancerous lesions
  • Obesity
  • Previous affection with breast cancer
• Epidemiology:
  • Natural history
• Histopathology:
  • Carcinoma may arise from the lobules, ducts, or nipple
  • Types:
    • Carcinoma of the ducts
    • Carcinoma of the lobules
    • Paget's disease of the nipple
    • Multicentricity and multifocality
• Classification of invasive carcinoma:
  • Paget's disease of the nipple
  • Invasive ductal carcinoma
  • Adenocarcinoma with productive fibrosis (scirrhous, simplex, no special type; NST)
  • Medullary carcinoma
  • Mucinous (colloid) carcinoma
  • Papillary carcinoma
  • Tubular carcinoma
  • Invasive lobular carcinoma
  • Rare cancers (adenoid cystic, squamous cell, apocrine)

Spread

• Local spread
• Lymphatic spread (by embolism and permeation)
• Blood stream spread

Hormone Receptors

• Oestrogen
• Progesterone