What the operation does
A microdochectomy — sometimes called single-duct excision — is the surgical removal of one specific milk duct from behind the nipple, usually because it is the source of persistent single-duct discharge or contains an intraductal papilloma (a benign wart-like growth inside the duct).
The operation is small and precise: a single duct is identified, traced back from the nipple, removed together with any growth inside it, and sent to the laboratory for analysis. The rest of the duct system, the nipple, and the surrounding breast tissue are left undisturbed.
It is one of the more routine breast operations in private practice. Most patients are home the same day with a small dressing on a peri-areolar wound; recovery is straightforward.
When microdochectomy is recommended
The operation is offered when:
- Persistent nipple discharge from a single duct — particularly if it is blood-stained or clear/serous (watery) — has been investigated with imaging and biopsy, and an intraductal lesion is the likely cause.
- An intraductal papilloma has been identified on imaging or biopsy. Most solitary papillomas are removed surgically rather than monitored, both to confirm the diagnosis on the whole specimen and to stop the discharge.
- Imaging shows a duct abnormality that warrants tissue diagnosis on the whole specimen rather than on a needle biopsy alone.
- Recurrent discharge that has not responded to conservative measures, where the patient and surgeon agree that surgery is the right step.
It is not the operation for multiple-duct discharge or bilateral nipple discharge — those situations have different causes (commonly duct ectasia or hormonal) and are usually managed without single-duct surgery. If multiple ducts are involved, a different operation — major duct excision — is sometimes considered.
For background on the assessment of nipple discharge, see nipple discharge assessment.
How the operation works
The principle is to remove the offending duct in continuity with any lesion inside it, while preserving the rest of the duct system and the nipple.
Identifying the right duct:
- The discharge itself is often used to identify the duct. By gently expressing the breast in the operating theatre, the offending duct can be seen producing fluid at the nipple, marked, and traced back.
- Pre-operative localisation — a fine probe is sometimes passed gently down the duct from the nipple to mark its course, particularly for ducts that are not actively discharging at the time of the operation.
- Imaging — most patients have already had mammography (where appropriate for age) and targeted retroareolar ultrasound as part of triple assessment. MRI is occasionally used when the duct or lesion is not visible on conventional imaging.
The incision:
- A small peri-areolar incision — along part of the natural border of the areola — gives access to the area behind the nipple where the ducts converge. The scar is well hidden in the natural change of skin colour at the areolar edge.
- Through this incision, the offending duct is identified and freed from the surrounding tissue.
- The duct is divided just behind the nipple and traced backwards (away from the nipple) for several centimetres, with any associated lesion contained within the specimen.
- The remaining tissue is closed in layers; absorbable stitches under the skin avoid the need for stitches to be removed afterwards.
Nipple sensation, breastfeeding, and other practical considerations
Because the operation is targeted on a single duct rather than the whole duct system, most patients retain normal nipple sensation and future breastfeeding is usually possible from the operated breast. Specific points worth understanding:
- Sensation is sometimes altered after surgery — numbness, tingling or increased sensitivity. This usually settles over a few weeks as the small nerves heal, but in a small minority of patients some altered sensation persists long-term. The risk is lower than for major duct excision because only one duct is removed.
- Breastfeeding uses many ducts, so removing one usually does not prevent later breastfeeding. The likelihood of full milk supply from the operated breast depends on how much surrounding tissue has been disturbed and on individual factors. For patients planning future pregnancies, this is worth discussing at consultation.
- Cosmetic outcome is usually excellent — a fine peri-areolar scar fades over a year. Patients with darker skin sometimes notice hyperpigmentation of the scar in the early months, which generally fades with time. Occasionally the nipple may flatten or retract slightly at the scar — this is unusual after a single-duct excision but more common with larger duct operations.
A small number of patients have recurrent discharge from a different duct in the months or years after a microdochectomy. This is uncommon and usually represents a separate small lesion in another duct rather than recurrence of the original problem. It is investigated and managed in the same way.