Breast — Viva Pearls and KUHS PYQs
High-Yield One-Liners
| Question / Stem | Answer |
|---|---|
| What type of gland is the breast? | Modified sweat gland |
| Location of breast | Superficial fascia of the pectoral region |
| Vertical extent of breast | 2nd rib to 6th rib |
| Horizontal extent | Lateral border of sternum to midaxillary line |
| Nipple level | 4th intercostal space, 10 cm from midline |
| Number of lobes in breast | 15–20 |
| What are Montgomery’s tubercles? | Enlarged sebaceous glands of the areola during pregnancy |
| Axillary tail of Spence passes through | Foramen of Langer |
| Retromammary space is filled with | Loose areolar tissue (allows free movement of breast) |
| Three muscles deep to the breast | Pectoralis major, serratus anterior, external oblique |
| Suspensory ligaments of Cooper connect | Dermis → ducts of breast → pectoral fascia |
| Most common site of carcinoma breast | Upper lateral quadrant (~60%) |
| Most common cancer in females | Carcinoma of the breast |
| Age group most affected | 40–60 years |
| Origin of carcinoma breast | Epithelial cells of lactiferous ducts |
| Peau d’orange is caused by | Obstruction of superficial lymphatics |
| Skin dimpling / retraction caused by | Infiltration of suspensory ligaments of Cooper |
| Nipple retraction caused by | Infiltration and fibrosis of lactiferous ducts |
| Breast fixity caused by | Infiltration of retromammary space and pectoral fascia |
| Krukenberg’s tumour | Secondary tumour in ovary from inferomedial quadrant via subperitoneal plexus |
| Route of brain metastasis from breast | Posterior intercostal veins → vertebral venous plexus → brain |
| Proportions of lymphatic drainage | 75% axillary, 20% internal mammary, 5% posterior intercostal |
| Subareolar plexus of Sappey drains into | Anterior (pectoral) axillary lymph nodes |
| Most important lymph node in breast cancer | Anterior axillary (pectoral) group |
| Surgical incisions in breast are made | Radially (to avoid cutting lactiferous ducts) |
| Milk secretion controlled by | Prolactin (not neural control) |
| Gynaecomastia associated with | Hormonal imbalance; Klinefelter’s syndrome |
| Development origin of breast parenchyma | Ectodermal (mammary ridge) |
| Development origin of breast stroma | Mesodermal |
| Milk line extends from | Axilla to groin |
KUHS PYQ-Style Questions and Model Answers
Q1. Describe the lymphatic drainage of the breast. Add a note on its clinical importance.
Lymphatics in two groups:
Superficial: drain skin of breast (not nipple/areola)
Deep: drain parenchyma, nipple, areola; include subareolar plexus of Sappey
Routes:
- Lateral quadrants → anterior axillary nodes (75% total)
- Medial quadrants → internal mammary nodes (20%)
- Lower lateral → posterior intercostal nodes (5%)
- Lower medial → subperitoneal plexus
- Deep surface → through pectoralis major and clavipectoral fascia → apical axillary nodes
Clinical importance:
- Carcinoma spreads predominantly via lymphatics
- Upper lateral quadrant (60% of cancers) → axillary nodes first → basis of axillary dissection in mastectomy
- Medial quadrant cancer → internal mammary nodes → cannot be accessed in routine axillary dissection → worse prognosis
- Cross-communication → bilateral involvement
- Subperitoneal plexus → Krukenberg’s tumour in ovary
Q2. Describe the clinical signs of carcinoma breast and give the anatomical basis of each.
| Sign | Anatomical Basis |
|---|---|
| Painless hard lump | Tumour mass |
| Fixity of breast | Infiltration of retromammary space and pectoral fascia |
| Skin dimpling/retraction | Shortening of suspensory ligaments of Cooper |
| Nipple retraction | Fibrosis and shortening of lactiferous ducts |
| Peau d’orange | Obstruction of superficial lymphatics → skin lymphoedema |
| Bilateral involvement | Cross-communication of superficial lymphatics |
Q3. What is the arterial supply of the breast?
Three sources:
- Internal thoracic artery — perforating branches through 2nd, 3rd, 4th intercostal spaces (main supply)
- Axillary artery — via lateral thoracic, superior thoracic, and acromiothoracic branches
- Posterior intercostal arteries — lateral branches
Q4. What is the structure of the breast?
Breast consists of three components:
- Skin — nipple (smooth muscle, 4th ICS) + areola (sebaceous glands, Montgomery’s tubercles)
- Stroma — suspensory ligaments of Cooper (fibrous) + fat (bulk of breast; absent under nipple and areola)
- Parenchyma — 15–20 lobes, each drained by a lactiferous duct; ducts expand to form lactiferous sinuses near nipple; each lobe = lobules of acini; myoepithelial cells facilitate milk flow
Q5. What is Krukenberg’s tumour?
A secondary malignant tumour of the ovary arising from spread of breast carcinoma (from the inferomedial quadrant). The pathway: inferomedial quadrant lymphatics → pierce anterior abdominal wall → communicate with subperitoneal lymph plexus → cancer cells migrate transcoelomically and deposit on the ovary.
Q6. What is the retromammary space? What is its clinical significance?
A space filled with loose areolar tissue between the breast and the pectoral fascia (covering pectoralis major).
- Allows the normal breast to move freely over pectoralis major
- Provides the surgical plane for simple mastectomy
- When carcinoma infiltrates through this space into pectoral fascia → breast becomes fixed and immobile — sign of advanced carcinoma
Q7. What is gynaecomastia? What are its causes?
Enlargement of breast tissue in males. Mainly at puberty; usually bilateral.
- Cause: hormonal imbalance — excess oestrogen relative to androgens
- Klinefelter’s syndrome (47,XXY)
- Liver cirrhosis, oestrogen-secreting tumours
- Drugs: spironolactone, cimetidine, digoxin, anabolic steroids
Exam-Favourite Tables
Carcinoma Breast — Sign vs Cause
| Sign | Structure Involved |
|---|---|
| Skin retraction/dimpling | Suspensory ligaments of Cooper |
| Nipple retraction | Lactiferous ducts |
| Peau d’orange | Superficial lymphatics |
| Breast fixity | Retromammary space + pectoral fascia |
| Bilateral spread | Cross-communicating superficial lymphatics |
Lymphatic Drainage Percentages
| Group | % |
|---|---|
| Axillary nodes | 75% |
| Internal mammary nodes | 20% |
| Posterior intercostal nodes | 5% |