What is the differential diagnosis for a red swollen breast?
The differential diagnosis includes infection, inflammatory breast cancer, history of prior radiation, and lymphatic or vascular obstruction. The history of prior radiation should be easy to corroborate with the patient. Patients with infection and inflammatory breast cancer can present with similar histories: a red, swollen, tender breast. Imaging should be performed to exclude a mass or an abscess. If the patient’s symptoms do not improve with antibiotic treatment, inflammatory breast cancer should be excluded. The skin appears red and swollen in inflammatory carcinoma because the dermal lymphatics are infiltrated with tumor cells. Typically, a punch biopsy of the skin confirms the diagnosis, although occasionally, punch biopsy results may be falsely negative.