B01 NIPPLE DISCHARGE OR INVERSION MBBS Final MB (Surgery) (Felix PY Lai)

1. Lactation: Normal milk production during pregnancy and post-partum, can continue for up to 2 years after delivery. Bloody discharge can occur in 20% of women during the 2nd or 3rd trimester and is usually benign.

2. Galactorrhea: Milky discharge unrelated to breastfeeding, often bilateral and caused by hyperprolactinemia due to hypothalamic-pituitary disease, drug-induced factors, or miscellaneous causes like stress and hypothyroidism.

3. Pathological Nipple Discharge: Spontaneous, persistent unilateral discharge that can be serous, sanguineous, or serosanguineous. Common causes include intraductal papilloma, duct ectasia, and fibrocystic changes, with malignancy in 5-15% of cases, most commonly DCIS.

Galactorrhea is a milky discharge unrelated to breastfeeding, commonly manifesting as bilateral milky nipple discharge involving multiple ducts.

Common causes include:

• Hypothalamic-pituitary disease: Prolactinoma, tumors (Craniopharyngioma, metastatic cancer), infiltrative diseases (Sarcoidosis), head trauma/surgery.
• Drug-induced: Antipsychotics (Haloperidol, Risperidone), antidepressants (Amitriptyline, Clomipramine), antiemetics (Metoclopramide, Domperidone).
• Miscellaneous: Stress, hypothyroidism (decreased clearance of prolactin), chronic renal failure (decreased clearance of prolactin).

Pathological nipple discharge is characterized by spontaneous, persistent unilateral discharge that can be:

• Serous (clear or yellow)
• Sanguineous (bloody)
• Serosanguineous (blood-tinged)

Potential causes include:

• Intraductal papilloma (most common)
• Duct ectasia
• Fibrocystic breast changes

Malignancy is the underlying cause in 5-15% of cases, with DCIS being the most common associated malignancy.

• Straw-colored (yellow) or clear transparent (serous) discharge:
  • Intraductal papilloma: Classical presentation; muscularis arteries supply blood but lymphatics and veins are compromised, leading to transudate formation due to increased vascular pressure.
  • Duct ectasia: Presents with creamy cheesy discharge; can be multi-colored (green/blue/black) or occasionally blood-stained.
  • Underlying malignancy: Includes Ductal carcinoma-in-situ (DCIS) and Invasive ductal carcinoma (IDC).

• Bloody discharge:
  • Intraductal papilloma: Can cause bleeding.
  • Underlying malignancy: Includes Ductal carcinoma-in-situ (DCIS) and Invasive ductal carcinoma (IDC).
  • Fibrocystic breast changes: May include duct ectasia, intraductal hyperplasia, and plasma cell mastitis.

• Medical treatment:

  1. Prolactinoma: Treated with Bromocriptine or Cabergoline.
  2. Drug-induced discharge: Reassurance and continuation of the drug or taper/change medication.

• Surgical treatment:

  1. Prolactinoma: Transphenoidal resection if refractory to dopamine agonists or if the patient wishes to become pregnant.
  2. Microdochectomy: Excision of a single duct and its associated lobules, indicated for persistent spontaneous discharge.
  3. Major duct excision: Excision of all retroareolar duct, also indicated for persistent spontaneous discharge.

Congenital nipple inversion is usually bilateral and benign, resulting from the failure of underlying mesenchymal tissue to proliferate and project the nipple papilla outwards.

Acquired nipple inversion can be caused by:

1. Underlying malignancy
2. Inflammation, which includes:
   • Duct ectasia
   • Periductal mastitis
   • Subareolar abscess and periareolar fistula
   • Tuberculosis mastitis
   • Idiopathic granulomatous mastitis