Background: In the general population, the incidence of accessory breast tissue, a congenital malformation, is 1-5%. The most common site is the lower axilla. Detecting such tissue may be problematic, and accessory breasts below the umbilicus are extremely rare.
Case: This report describes the case of a 5-day postpartum 29-year-old woman, G2P2, with painful vulvar swelling 6 cm in diameter. The patient was diagnosed with polymastia in the vulva, without polythelia, with galactostasis due to suturing of a birth laceration covering an excretory duct. The sutures were removed, and the pain decreased. Breastfeeding was continued.
Conclusion: Ectopic breast tissue is rare but should be taken into consideration in the differential diagnosis of a vulvar mass, especially postpartum in lactating women.