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Mammary duct ectasia is a chronic inflammatory condition characterized by dilatation of the terminal (subareolar) lactiferous ducts, with a peak incidence in women between 40–50 years of age. Although often asymptomatic, mammary duct ectasia may manifest with unilateral or bilateral nipple discharge, nipple inversion, or a subareolar mass. The diagnostic workup is based on the age-appropriate evaluation for pathological nipple discharge and/or a palpable breast mass. A biopsy may be required if imaging is inconclusive or depicts features concerning for malignancy. The typical histopathological features of duct ectasia include periductal inflammation, luminal secretions with/without inflammatory infiltrate, and foamy histiocytes. As most cases resolve spontaneously, expectant management is usually appropriate. Surgical excision of the affected duct may be considered for symptomatic control.
Inspissated luminal secretion → stasis → periductal inflammation → fibrous obliteration
- Pathological nipple discharge and/or palpable breast mass: Perform age-appropriate breast imaging.
- Imaging findings concerning for malignancy : biopsy
- Breast ultrasound: dilated subareolar ducts
- Mammography: dilated, tortuous subareolar ducts, branching calcifications
- Periductal inflammation and/or fibrosis
- The ductal lumens may be obliterated or filled with inspissated secretions and inflammatory cells.
- Foamy histiocytes are characteristically present within the inflammatory infiltrate.