A Rare Presentation of primary breast carcinoma in the vulva: a case report and literature review

Abstract

The primitive embryonic milk line, which derives from the ecto derm, extends from the axilla to the groin, including the vulva. It ap pears during the fifth week of embryonic development and regresses in later stages.1-4 The finding of ectopic mammary gland tissue along this line is unusual, with an estimated incidence of 1% in the general population, 0.22% to 0.6% in white individuals, and 3.5% in African American individuals.5,6 There are reports describing it in up to 6% of the population.5,6Ectopic mammary gland tissue responds to hormonal stimulation and undergoes the same physiologic and pathologic processes found in the normal breast; however, the development of a mammary gland carcinoma (MGC) in this tissue is an extremely rare event. The most common location of ectopic breast tissue is in the axilla and ectopic MGC is also found most commonly in this site, comprising 91% of the total. Ectopic MGC in the vulva is even rarer, with approximately 28 cases of this carcinoma reported in the literature.