ABSTRACT
INTRODUCTION AND IMPORTANCE: Ectopic breast tissue (EBT) may occur anywhere along the milk line, which extends bilaterally from the axilla to the groin. EBT can undergo the same physiologic and pathologic changes seen in normal breast tissues. The most common reported pathologies are carcinoma, inflammatory changes and fibroadenoma. CASE PRESENTATION: A painless slow growing swelling on the mons pubis of a young lady which was initially thought to be a lipoma but pathology showed it was ectopic breast tissue is reported. CLINICAL DISCUSSION: During normal development, mammary ridges form breasts in the pectoral region and their remainder regresses. Failure of regression of the remaining portions of the mammary ridges can lead to ectopic breast tissue development with (polythelia) or without (polymastia) a nipple-areolar complex. Ectopic breast tissue can occur anywhere along the mammary ridge but is most commonly found in the axilla; findings anywhere else outside of the axilla are rare. CONCLUSION: A high index of suspicion of ectopic breast tissue is required for swellings over the anatomic distribution of the embryologic milk line particularly if these swellings respond to hormonal changes in puberty, pregnancy and lactation.