Prenatal sonographic diagnosis of congenital perineal skin tag: case report and review of the literature.

BACKGROUND: Skin tags, or acrochordons, are benign, soft, fleshy tumors that are composed of hyperplastic epidermis covering a dermal connective tissue stalk.

METHODS: Case report of a congenital perineal skin tag that presented as a perineal tumor during second-trimester sonographic scan at 23 weeks' gestation. Literature review of the medical literature using Pubmed(R) and the search terms acrochordon, fibroepithelial polyp (FEP), and skin tag.

RESULTS: Routine midtrimester targeted organ scanning at 23 weeks' gestation revealed a 5-mm hypoechogenic elongated mass in the perineal area of the fetus. The lesion progressed to twice that size by 36 weeks. Detailed anatomy scan of the fetus was unremarkable, and amniocentesis demonstrated normal karyotype. The mother developed spontaneous labor at 38 weeks' gestation and delivered a phenotypically normal girl with a round smooth mass in the perineal area. The lesion was removed; pathologic examination revealed a lipomatous skin tag. Literature review showed skin tags associated with different medical conditions.

CONCLUSION: To the best of our knowledge, no prenatally diagnosed cases of this lesion on the fetal perineum have been published. In the present case, this was an innocuous finding.