Bone in the breast? Long term toxicity 21 years after interstitial brachytherapy as a boost

An 81-year-old patient developed an exulcerous tumor in her left breast 21 years after breast cancer treatment with lumpectomy and adjuvant radiotherapy. At the time of the initial treatment 21 years ago, whole breast irradiation was performed with a prescribed dose of 48 Gy and a maximal dose of 69 Gy. In addition, the patient received a 14.7 Gy boost with multicatheter brachytherapy as partial breast irradiation. In general, fat necrosis after radiotherapy, surgery or trauma is a minor problem for patients, but can lead to diagnostic difficulties. The incidence varies: the literature indicates that it occurs in up to 34% of cases. The direct pathogenesis is not clear; it can be due to high radiation dose to the breast, dosimetric inhomogeneities or surgical complications (seromas and inflammation). The tumor in the case described here, occurring more than two decades after the primary treatment, is a rarity in this extent and is an unusual clinical, radiological, and histological finding. It provides a good example of the need for an individualized approach to treatment.