What is Ductal Ectasia?
Ductal ectasia (also called mammary duct ectasia) is a benign breast condition characterized by dilation and inflammation of the mammary ducts beneath the nipple, most commonly affecting women in their fourth decade of life. 1, 2
Pathophysiology and Clinical Presentation
Ductal ectasia involves progressive dilation of the major breast ducts with periductal inflammation as the primary pathologic process, with the duct dilation itself being the outcome rather than the cause. 3 The condition affects 1-2% of all symptomatic breast presentations, though higher rates are seen in autopsy studies where normal age-related duct dilation is often misclassified. 3
Key Clinical Features
Patients present with one or more of the following manifestations:
- Nipple discharge that is spontaneous, unilateral, from a single duct, and typically clear, serous, sanguineous, or serosanguineous in character 1, 2
- Noncyclical breast pain described as exquisite continuous burning sensation behind the nipple with breast hypersensitivity, accounting for 25% of noncyclical mastalgia cases 1
- Subareolar mass or abscess formation with possible overlying inflammation 4, 5, 3
- Nipple retraction due to chronic ductal inflammation and fibrosis 4, 5
- Mammary fistula formation in advanced cases 4, 3
Epidemiology and Risk Factors
The condition accounts for 17-36% of cases of pathologic nipple discharge and most commonly affects women in their fourth decade, with 81% being pre- or perimenopausal. 1, 5 Heavy smoking is the most significant modifiable risk factor, with current smokers having three times higher odds of developing duct ectasia, particularly those with longer smoking duration. 1, 6
Diagnostic Approach
Imaging Evaluation
For women over 40, mammography is the initial imaging modality of choice, which may demonstrate duct ectasia or secretory calcifications at the site of symptoms. 1 The American College of Radiology recommends the following algorithmic approach:
- Mammography first for women over 40 with pathologic nipple discharge 1
- Ultrasound to evaluate dilated ducts and rule out other pathologies 1
- Ductography (galactography) may be performed before duct excision to characterize lesions responsible for symptoms 1
- MRI has higher positive and negative predictive values than ductography for detecting high-risk lesions and cancers in patients with pathologic nipple discharge 1
Critical Pitfall to Avoid
The risk of underlying malignancy increases with age, particularly in women over 60 years, and pathologic nipple discharge can be associated with malignancy in 5-21% of cases. 1 Failing to evaluate pathologic nipple discharge in menopausal women can lead to missed malignancy. 1 Up to 12% of patients with ductal carcinoma in situ present with nipple discharge. 1
Management
Conservative Management
For mild symptoms without concerning features, conservative management with reassurance is appropriate, as noncyclical mastalgia due to duct ectasia tends to be of shorter duration than cyclical mastalgia, with spontaneous resolution occurring in up to 50% of patients. 1 Most cases do not respond to hormonal manipulation. 1
Surgical Management
Surgical duct excision is recommended for pathologic discharge, even with negative imaging, as this provides both diagnosis and treatment. 2 Excision of the central mammary tissue and larger ducts has been used for clinical manifestations of abscess, fistula, and nipple discharge with good results. 4 For subareolar abscesses, excision of the entire focus and corresponding duct appears superior to simple incision and drainage, which has higher failure rates. 5
Role of Antibiotics
Antibiotics effective against anaerobic organisms (which appear to play a role in the periductal inflammation) are effective in resolving periareolar inflammation and are useful when combined with surgery in mammillary fistula cases. 3
Differential Diagnosis
Breast cancer is the most important differential diagnosis, particularly in older women. 4 If the clinical picture resembles cancer, diagnostic biopsy is necessary, as imaging alone is unreliable for predicting histology. 1