Invasive lobular carcinoma in a breast hamartoma.

Hamartomas are uncommon benign breast neoplasms. We report the first case, to our knowledge, of invasive lobular carcinoma arising in a breast hamartoma. This case illustrates the importance of careful interpretation of the clinical and mammographic findings. A more aggressive approach toward the management of breast hamartomas is not justified when clinical and mammographic findings are consistent with classic hamartomas.