[Rare heterochromosomal anomaly: male XX syndrome in association with adenocarcinoma of the breast. Preliminary considerations].

A case of a male patient with an XX chromosome picture is presented. This anomaly is extremely rare and accompanied, as in the reported case, by morphological and structural alterations of the testicles: tubular fibrosis and germinal aplasia; disturbances of hormone secretion: FSH, LH, testosterone and 17-ketosteroid values were nearer those normally found in females; sex chromatin. The case was rendered more interesting by the simultaneous presence of adenocarcinoma of the breast, which is 100 times less common in males. Statistical evidence is cited for the proposition that this neoplasia has an underlying genetic and endocrine component.