Challenges in Diagnosing Inflammatory Breast Cancer

Abstract and Introduction

Abstract

Objective: The purpose of this narrative review is to summarize the contributors to misdiagnosis or delayed diagnosis of inflammatory breast cancer (IBC) and strategies for expedient diagnosis.

Background: Patients with IBC often report the disease as initially being misdiagnosed, most commonly as mastitis.

Methods: We reviewed the literature on this challenging diagnosis by using sequential PubMed search criteria including IBC breast symptoms, IBC diagnosis, and IBC imaging modalities to augment the authors' knowledge of IBC. Other references were added from the manuscripts identified in the PubMed searches and from manuscript reviewers.

Conclusions: Several factors contribute to the delayed diagnosis of IBC. One important factor is that IBC is uncommon, and many generalists may not be aware of it in the differential diagnosis of breast skin symptoms. Several features of IBC contribute to the low sensitivity of mammography for its detection, and so the diagnosis is based on clinical factors and is thereby subjective. The presentation can be highly varied; classic textbook images that do not capture the range of presenting signs and symptoms across skin tones may contribute to missed diagnoses in patients with atypical presentations. In fact, the staging system of the American Joint Committee on Cancer, which requires erythema of the breast skin for diagnosis, may exclude patients with obvious global breast skin findings that are not explicitly red. We present an adapted algorithm for working up the undiagnosed inflammatory breast to ensure the timely and accurate diagnosis of IBC. We assert that frank, non-erythematous global skin signs in an enlarged breast with diffuse breast malignancy are sufficient to diagnose IBC if the timing of these signs and findings on biopsy are consistent. We further provide images of atypical IBC identified by global breast skin signs, including peau d'orange, consistent with IBC in the absence of frank erythema.

Introduction

Inflammatory breast cancer (IBC) is a virulent subtype of invasive breast cancer that typically presents with breast skin symptoms such as erythema and edema of the breast skin. It is a crucial diagnosis to rule out when someone presents with a red or inflamed breast, but it can be a difficult diagnosis to make, both at presentation and even after a diagnosis of malignancy.^[1] Our objective is to review the literature highlighting factors that contribute to the difficulty of making this diagnosis and to provide updated guidance on how to avoid these challenges. Briefly, we note that the likelihood of a generalist ever seeing a case of IBC is very low, which increases the risk that it may be overlooked on the differential diagnosis for inflammatory breast symptoms. The risk of misdiagnosis is further increased by the low sensitivity of mammography, the most commonly ordered screening exam for breast lesions suspected of being malignant.^[2,3] This means physicians who suspect cancer may be wrongly reassured by false-negative findings on a mammogram and miss the diagnosis of IBC instead of moving on to ultrasonography, magnetic resonance imaging (MRI), and biopsy when needed.^[4] In addition, when malignancy is identified, it can often be misdiagnosed as non-IBC owing to subjectivity in the diagnosis of IBC, heterogeneity in presentation of IBC, and, perhaps, an overly rigid staging system requiring erythema and concurrent edema and peau d'orange to make the diagnosis.^[5–8] These factors greatly complicate reporting of IBC and research as well, and efforts are under way to refine the diagnosis. We present the following article in accordance with the Narrative Review reporting checklist (available at https://dx.doi.org/10.21037/cco-21-116).