Accessory nipple in four-month-old infant
My 4 month old appears to have polythelia, an accessory nipple, very small and faint, but definite. Can you give me any information about this?
Polythelia (extra nipples) and polymastia (extra glandular breast tissue) are common developmental abnormalities of the breast and nipple which usually present as small lesions along the mammary line, an embryologic line that extends bilaterally from the axillary regions (armpit) to the inguinal ligaments (groin) and into the vulvar area in females. They are usually benign skin birth defects that are left alone until after puberty.
In most patients I see, extra nipples look like skin moles that women say have been there "as long as I can remember." Infrequently there can be some associated, extra breast glandular tissue development when she undergoes normal breast development at puberty.
Again this isn't usually a problem because the amount of glandular tissue is usually very minimal. If it does become a cosmetic problem for her in later life, which in most cases it does not, she can choose to have it removed as a simple, outpatient procedure.
I was not aware of any other conditions or anomalies associated with polythelia so I did a literature search. Apparently there is a low incidence of some association with underlying kidney and urinary tract defects. See abstract below. Keep in mind that the one study only found about 8% of patients with polythelia/polymastia having any renal/urinary defects. You should mention this to your pediatrician to be sure he or she is aware of it.
Urbani CE, Betti R
Accessory mammary tissue associated with congenital and hereditary nephrourinary malformations.
Int J Dermatol 1996 May;35(5):349-352: Dermatology Service, Hospital San Raffaele Resnati, Milan, Italy.
BACKGROUND AND OBJECTIVES. The association between polythelia (supernumerary nipple) and kidney and urinary tract malformations (KUTM) is controversial. Some authors reported this association in newborns and infants. Case-control studies dealing with adult subjects are not found in the literature. The purpose of this study is to determine the frequency of the association between accessory mammary tissue (AMT) and congenital and hereditary nephrourinary defects in an adult population compared to a control group.
METHODS. The study was performed in 146 white patients (123 men, 23 women) with AMT out of 2645 subjects consecutively referred to us for physical examination. The following investigations were undertaken: ultrasonographic examination of the abdomen and the kidneys, ECG, echocardiogram, roentgenogram of the vertebral column, urinalysis, and other laboratory tests. A sex and age-matched control group without any evidence of AMT or lateral displacement of the nipples underwent the same examinations.
RESULTS. Kidney and urinary tract malformations were detected in 11 patients with AMT (nine men, two women) and in one control. These data indicate a significantly higher frequency of KUTM in the AMT-affected patients compared to controls (7.53% vs. 0.68%).