Distinguishing Mastitis from Inflammatory Breast Cancer

Clinical Presentation and Diagnostic Approach

The American College of Radiology recommends assessing for asymmetry compared to the contralateral breast during physical examination of a woman with mastitis or suspected inflammatory breast cancer 1
The American College of Radiology suggests evaluating whether any mass is three-dimensional and distinct from surrounding tissue during physical examination 1
The American College of Radiology advises checking for skin dimpling or attachment to deep fascia during physical examination 1
A history of mastitis not responding to at least 1 week of antibiotics should raise suspicion for inflammatory breast cancer, according to the Annals of Oncology 2
Rapid onset of symptoms (duration less than 6 months) with erythema, edema, or peau d'orange is a red flag for malignancy, as reported in the Annals of Oncology 2
The National Comprehensive Cancer Network recommends core needle biopsy or skin punch biopsy in cases with persistent symptoms or high clinical suspicion to confirm or exclude malignancy 2, 3

Patients may have a history of mastitis that does not respond to at least one week of antibiotics, and may present with symptoms such as focal sensitivity in the breast and erythema or hyperpigmentation of the overlying skin, with antecedents of nipple retraction or crust formation 4
Examination may reveal erythema occupying at least one-third of the breast 4

Ultrasound is useful for distinguishing fluid-filled cysts from solid masses, and may be indicated for patients with worsening or recurrent symptoms 5
Mammography may be indicated based on age and risk factors, although its role in mastitis diagnosis is limited 5

Regular exercise, including weight training, is recommended to maintain overall breast health, according to the guidelines from the American College of Obstetricians and Gynecologists 5

The American Society of Clinical Oncology recommends evaluating the duration of symptoms, as symptoms lasting less than 6 months with erythema occupying at least one-third of the breast, may indicate inflammatory breast carcinoma in patients, particularly in those with a history of breast symptoms 6, 7
A history of poor response to antibiotics, with no improvement after at least 1 week of treatment, should raise suspicion of malignancy in patients with breast symptoms 6

The American Academy of Pediatrics suggests that ultrasound of the breast is indicated in immunocompromised patients, those with worsening or recurrent symptoms, and when an abscess is suspected, which occurs in approximately 10% of mastitis cases 8, 8

The European Society for Medical Oncology recommends ruling out malignancy in women aged 45 years, as this age group is at risk for inflammatory breast carcinoma, and a biopsy or mammography may be necessary based on clinical suspicion and risk factors 6, 7