A non-Cowden syndrome associated giant hamartoma of the breast in a young breast cancer patient
Rumpf A.-L.1, Mathiak M.2, Schäfer F.3, Farrokh A.1, Elessawy M.1, Bauerschlag D.1, Maass N.1, van Mackelenbergh M.1, Caliebe A.4, Heilmann T.1
1UKSH Kiel, Department of Gynecology and Obstetrics, Kiel, Deutschland, 2UKSH Kiel, Institute for Pathology, Kiel, Deutschland, 3UKSH Kiel, Department of Breast Imaging and Interventions, Kiel, Deutschland, 4UKSH Kiel, Department of Human Genetics, Kiel, Deutschland

A 36-year old young female presents with a giant hamartoma of the left breast. She suffered from an early breast cancer of the contralateral breast before, which was treated with breast conserving therapy, radiation, and endocrine therapy ever since.
A hamartoma itself does not classify as a marker for an increased relative risk for developing breast cancer. But importantly, there is an unveiled genetic pathology linking multiple or bilateral hamartomas to breast cancer: The PTEN hamartoma tumor syndrome (PHTS), which describes a mutation in the PTEN tumor suppressor gene, leading to a drastically increase in breast cancer lifetime risk of 67-85% and development of hamartomas in different tissues of the body.
Materials: Breast imaging and biopsy. Tumor resection. Utilization of literature. Genetic testing.
Methods: Tumor resection was performed via a reduction mammoplasty utilizing a superomedial pedicle technique for the nipple areola complex, including an inverted T-scar incision. The areola complex was preserved and reduced in adaption to the right breast.
A genetic testing for loss of PTEN was performed.
Results: The hamartoma had a weight of 700gr with a size of 15cm and was resected in sano with a good cosmetic outcome. The genetic testing excluded a loss of PTEN function.
Conclusion: Giant hamartomas should be removed to avoid long-range deformity of the breast.
The presence of a mammary hamartoma might indicate a genetic testing.