Seroma of the Mammary Gland

Inclusion criteria study group and control group 1: * Written informed consent * Age ≥ 18 years * all stages of DCIS or primary breast cancer (T1-T4, N0 or N+, M0) including all histopathological subtypes (ER/PR positive, ER positive/PR negative, Her-2/neu positive and triple negative) * Surgical procedure planned including ablatio or subcutaneous mastectomy with implant or expander insertion Inclusion criteria control group 2 and 3: * Written informed consent * Age ≥ 18 years * Surgical procedure planned with implant or expander insertion with or without subcutaneous mastectomy Exclusion criteria: * Age \<18 years * Male sex * Breast cancer patients planned for breast conserving therapy * Recurrent breast cancer disease * History of breast surgery * Diagnosis of LCIS only * Pregnancy at time of diagnosis * Patients with a known immunodeficiency