Disease Description (Causes and Symptoms)

Definition: A condition in which the nipple is indented toward the breast rather than protruding outward (unilateral or bilateral).
Prevalence: Reported in approximately 2% worldwide and approximately 3% domestically.
Pathophysiology/Causes:
- Congenital: The milk ducts (mammary ducts) are underdeveloped and shortened, pulling the nipple inward.
- Structural: The fibrous tissue supporting the area beneath the nipple is weak, or rare fibrous bands pull the nipple downward.
- Acquired: May occur due to tissue fibrosis caused by inflammation (such as a breast abscess) or a breast mass (especially breast cancer) — if it newly develops after not having been present before, malignancy must be ruled out.
Severity classification (general classification):
- Grade 1: Easily protrudes when pulled by hand and remains protruded.
- Grade 2: Protrudes when pulled by hand but soon becomes inverted again.
- Grade 3: Severely inverted, difficult to evert even by hand, and immediately becomes inverted again even after being everted.
Main symptoms/Effects:
- Cosmetic problems
- Breastfeeding difficulties (difficulty for the baby to latch)
- Hygiene problems (risk of inflammation due to retained secretions)
- Possible changes in sexual sensation

Treatment Methods

Nonsurgical treatment
- Use of conservative corrective devices (nipple suction devices, traction devices) — may be attempted in mild cases.
- Nipple shields (during breastfeeding) and appropriate breast hygiene.
- Topical products (nipple moisturizing/healing creams) may be used, but ingredients should be checked before use during pregnancy or breastfeeding (possible effects on the fetus/newborn).
Surgical treatment
- Simple release procedure (incision and release of fibrous tissue beneath the nipple) followed by fixation with sutures — commonly used for mild to moderate cases.
- Nipple splitting procedure and rearrangement of internal tissue (in severe cases) — performed for recurrent or severe inversion.
- The surgical method is selected based on the degree of inversion, history of recurrence, and desire to breastfeed.
Precautions/Side effects
- Possibility of inability to breastfeed after surgery (especially when the milk ducts are cut).
- Possibility of recurrence and surgical complications such as bleeding, infection, and congestion.
- Ingredient safety must be checked when using topical products during pregnancy or breastfeeding.
Follow-up examinations
- Newly developed inverted nipples that were not present previously require evaluation for malignancy with imaging (mammography and ultrasound) and, if necessary, a biopsy.

Materials/Information to Prepare
- List of currently used medications (including hormone medications)
- Previous breast-related test results (mammography, ultrasound, biopsy results, etc.) or imaging films/reports
- When the symptoms began and how they have progressed (whether they appeared suddenly or worsened gradually)
- Whether only one side has changed or both sides
- Breastfeeding status and pregnancy plans
- Record of whether there is a palpable lump or discharge from the breast (including bloody discharge)
- If possible, a photo of the current condition (may help when consulting with medical staff)
Items useful to record for the outpatient visit
- Whether pain, discharge, redness, or fever is present
- History of previous breast surgery or injury, and family history (such as breast cancer)

Is this condition congenital or acquired? If it developed recently, what additional tests are needed?
Will surgery affect breastfeeding? How do you distinguish cases in which breastfeeding is possible from those in which it is not?
How likely are nonsurgical corrective devices (nipple shields/traction devices) to be helpful?
What are the risks of surgery (bleeding, infection, changes in sensation), and what is the recurrence rate?
What side effects or precautions should be considered when using topical creams or prescription medications?

Only one nipple has recently started to become inverted. How likely is this to be a sign of breast cancer? Which test should be performed first?
I am planning to become pregnant and breastfeed in the future. Which surgical method do you recommend to preserve breastfeeding function as much as possible?