not to misdiagnose inflammatory breast cancer on imaging : challenging facts for radiologistes

Hadhami Rouiss, Anja Jabeur, Nesrine Souayah, Amira Lika(*), Ines Trabelsi(*), Chaouki Mbarki, Hajer Bettaieb

University of Tunis el Manar, Faculty of medicine, Gynecology and Obstetrics department, Ben Arous Regional Hospital, Tunis, Tunisia

(*)University of Tunis el Manar, Faculty of medicine, Department of anesthesiology and reanimation,, Ben Arous Regional Hospital, Tunis, Tunisia

Introduction :

Inflammatory breasts are a difficult problem because of their ambiguous significance. Few articles in the literature treat inflammatory breast pathology, which remains relatively poorly understood. Every radiologist's main concern is not to miss diagnosis cancer.

objective : to study the radiological particularities of inflammatory breast cancer compared with other inflammatory breast pathologies.

Design : it was a retrospective, monocentric, longitudinal observational study

Method : The study included patients followed for inflammatory breast disorder who had undergone radiological and histological investigations over a 5-year period. Puerperal mastitis, known secondary inflammatory cancers and cysts were excluded.

Results : During the study period, 864 patients were treated for breast pathology. We identified 55 cases of inflammatory mastitis, representing an incidence of 6.36%. Breast cancer was diagnosed in 6 of these patients (10.9%). Ultrasound was performed in 87.3% of cases (n=48). Three cases were classified as ACR5. Eleven patients were classified as ACR4 in the presence of complex masses, dendritic branching or a complex cystic mass: 3 cases were ACR4c and 3 cases were ACR4b. ACR3 classification was found in 22 cases, due to the presence of collections in 10 cases, and ductal ectasia with echogenic content in 12 cases. The remaining patients were classified as ACR2 in 10 cases and ACR1 in 2 cases. Patients with retrospectively confirmed cancer were classified as at least ACR 4c, i.e. 3 cases of ACR 4c and 3 cases of ACR 5. A heterogeneous hypoechoic nodule was found in 3 cases. Microcalcifications were found in only one case. Stellate distortion were found in 3 cases and irregular contours in 3 cases. Posterior attenuation was found in one case. The presence of adenopathy was noted in 02 cases. Areas of necrosis were reported in one case. Breast MRI was performed in one patient for diagnostic purposes in view of the atypical presentation and the patient's young age (40 years). This enabled the breast assessment to be reclassified as ACR3, having initially been classified as ACR4c on breast ultrasound, with an appearance of granulomatous mastitis presenting as a breast pseudotumor. Five radiological findings led to a differential diagnosis of breast cancer. Their definitive diagnosis were granulomatous mastitis in 4 cases: 3 classified ACR 4b and one patient ACR4c reclassified ACR 3 after MRI and one patient with cytosteatonecrosis classified ACR4a. Patients classified ACR 3 had as definitive diagnosis either abscessed infectious mastitis, purulent galactophoritis or granulomatous mastitis.

Discussion :

The semiology of mammographic abnormalities in favour of malignancy has been widely described in the literature, the most frequent sign consisting of skin thickening, found in 84% of cases in the Günhan-Bilgen study [1]. This thickening, which is often more marked in the case of small breast volumes, initially predominates in the inferior areolar region before rapidly spreading to the entire skin envelope [2]. The second most common sign is trabecular thickening, noted in 81% of cases [3]. Microcalcifications in inflammatory cancer can take on very different forms, with a diffuse distribution of benign microcalcifications in around 10% of cases. However, when they are present, they are most often ACR4 or even 5 [3]. Another frequently noted sign is nipple retraction, visible in 43% of cases on mammography [1], which is entirely consistent with the rate of clinical nipple retraction found.

The main ultrasound sign in favour of malignancy is skin thickening. The high-frequency probe can be used to authenticate skin thickening in 95% of cases, which is more sensitive than mammography [2]. The second essential ultrasound sign is an overall increase in the echogenicity of the breast parenchyma, related to oedema and thickening of Cooper's ligaments [1]. Ultrasound can of course detect masses in 80% of cases. In some inflammatory breasts that are resistant to medical treatment, although no real mass is identified, isolated areas of attenuation can be seen, which should be identified and biopsied [1]. Other less decisive signs may be identified, such as dilation of vessels and lymphatics in 68% of cases, or pectoral involvement. Lastly, one of the essential features of ultrasound is its ability to analyse lymph nodes, not only in the axilla but also above and below the clavicle, and even in the internal mammary glands.

Conclusion: The radiological diagnosis of inflammatory breast cancer can be contentious. Granulomatous mastitis and cytosteatonecrosis are the most misleading findings. 

Références :

1. Günhan-Bilgen I, Ustün EE, Memis A. Inflammatory breast carcinoma: mammographic, ultrasonographic, clinical, and pathologic findings in 142 cases. Radiology.2002;223(3):829—38.
2. Le-Petross CH, Bidaut L, Yang WT. Evolving role of imaging modalities in inflammatory breast cancer. Semin Oncol.2008;35(1):51—63.

1. Kushwaha AC, Whitman GJ, Stelling CB, Cristofanilli M, Buzdar AU. Primary inflammatory carcinoma of the breast: retrospective review of mammographic findings. AJR Am J Roentgenol.2000;174(2):535—8.