Apocrine adenosis of the breast: clonal evidence of neoplasia

Aims: We report here a case of apocrine adenosis of the breast in a 66-year -old woman. To clarify the nature of this lesion, we examined it by clonal analysis, Methods and results: The lesion, 43 mm at its greatest dimension, was ill-c ircumscribed, lacking a fibrous capsule, and was composed of compact glands that showed typical histological features of apocrine adenosis. Clonality analysis, using the polymerase chain reaction (PCR)-based method for female s heterozygous for a BstXI polymorphism of the X-linked phosphoglycerokinas e (PGK) gene, revealed the monoclonal nature of the lesion. Conclusions: This result strongly suggests that some populations of apocrin e adenosis are already neoplastic, and this could contribute to the premali gnant potential of this lesion.