FAMILIAL ABERRANT MAMMARY TISSUE - A CLINICOEPIDEMIOLOGIC SURVEY OF 18 CASES

Background: Aberrant mammary tissue (AMT) is a common minor cutaneous anomaly located along the embryonic mammary line, It may be sporadic, familial or associated with nephrourinary malformations, Objective: To investigate the frequency of family history of AMT and its possible i nheritance, Methods: We investigated a population of 156 adult Caucasi an subjects affected with AMT. The familial background was evaluated p rimarily by using a questionnaire and by direct study of family member s when available. Renal ultrasound examination was also performed to d isclose the presence of kidney and urinary tract malformations. Result s: Eighteen patients (11.5%), 12 males and 6 females, had one relative with AMT (parents: 8, sons: 5, brothers/sisters: 3, other: 2). A male -to-male transmission was found in 9 cases (75%), female-to-female and female-to-male ones in 2 cases and a male-to-female one in 1 case. No patient had nephrourinary defects, Conclusions: The frequency of fami lial AMT in our study is very high and reflects both racial factors an d the large number of the subjects surveyed. There is no distinctive c linical pattern for familial AMT, although pseudomamma (13 cases, 72%) and the left-sided location of the defect (66%) may suggest a 'heredi tary predisposition'. Inheritance is consistent with an autosomal domi nant transmission, although an X-linked dominant transmission is also possible. Finally familial AMT does not seem to be related to a higher association with nephrourinary malformations.