How to Define Inflammatory Breast Cancer: A Systematic Review

The diagnosis of IBC is clinical and mainly based upon skin changes. This definition may vary from one clinician to another and one patient to another. Due to the obscure criteria available for diagnosing IBC, in this review, we gathered all the reliable information in the literature about the definition of IBC in the last decade to identify important features that should be considered in the diagnosis. We conducted this systematic review on MEDLINE and PUBMED by searching for the keywords "inflammatory breast cancer," "diagnosis," "criteria," or "definition." The time limit of this study was 13 years, from 2010 to 2023. Our basic search revealed 158 articles and finally 24 studies were approved and evaluated. The prevalence of clinical signs and symptoms and imaging and pathologic features were analyzed. The clinical criteria for the definition and diagnosis of IBC were mentioned in 100% of the studies, with the most common being skin changes (erythema, edema, and peau d'orange) in all 24 articles, rapid onset (< 6 months) in 66.6% of the studies, and involvement of at least one-third of the breasts in 41.6% of the studies. The imaging criteria for IBC diagnosis were discussed in 11 studies (45.8%), with the most common imaging sign being diffuse involvement of the breast and skin thickening (72.7%). Five studies (20.8%) evaluated the role of magnetic resonance imaging (MRI) in the diagnosis of IBC and reported the following findings: heterogeneous enhancement, edema on T2-weighted images, asymmetrical enhancement, diffuse non-mass enhancement, skin enhancement, and Cooper's ligament enhancement. Pathology-specific findings were common in 10 articles (41.6%), which included dermal/non-dermal lymphatic tumor emboli. This study suggested that IBC should be suspected in the presence of rapid-onset (at least less than 6 months) erythema and edema, regardless of its extent, and when suspected, mammography and ultrasound should be performed to search for diffuse skin or parenchymal involvement, multicentric disease, and suspicious regional lymph nodes. MRI and skin biopsy could be helpful when the diagnosis is not clear (e.g., no underlying mass).