Ultrasound features of the inflammatory mastitis

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 :

Mammography and ultrasound should be used as the first line of disgnostic tools for any inflammatory breast, as the abnormalities detected are often aspecific and do not allow a definitive aetiological diagnosis to be made. However, certain signs should be carefully looked for in order to give early indications of a benign aetiology or carcinomatous mastitis.

Objective: to describe the ultrasound features of inflammatory mastitis

Design : This was a retrospective, monocentric, longitudinal observational study.

Method: We compiled a list of patients followed for inflammatory syndrome who had undergone radiological and anatomopathological exploration over a 5-year period. Puerperal mastitis, cysts and known secondary inflammatory cancers were excluded.

Results

Ultrasound was performed in 48 cases. A mass was found in approximately 25.4% of patients. A collection was noted in 18.1% of patients. A complex solid and cystic breast mass was found in one patient (1.8%). A hypoechoic and heterogeneous area was noted in 18.1% of patients. An echogenic lesion suggestive of an abscess was found in 7.2%. Ductal ectasia was identified in 21.8% of patients. Fibrocystic was reported in 9% of patients. A simple cyst was found in 12.7% of patients. Aspecific inflammatory ultrasound findings such as skin thickening and infiltration of adjacent breast tissue were observed in 3.6% and 10.9% of patients respectively. Fistulae were noted in 7.3% of patients. Adenomegaly was found in 14.5% of patients. Ultrasound examination revealed masses in 25% of cases. The average size of the masses was 30.5 mm long axis [2mm-60mm]. The lesion was hypoechoic in 57.1% of masses, hyperechoic in 14.2% and mixed heterogeneous in 28.7%. The shape was irregular in 63.15% of masses, oval in 21% and round in 15.8%. The margins were: indistinct or poorly defined, blurred in 21.4% of masses, sharp in approximately 28.5% of masses, spiculated in 28.7% of masses, and lobulated in 21.4% of cases. Six masses revealed vascularity on color Doppler. One mass showed attenuation and no posterior acoustic enhancement was mentioned. In 18.1% of cases, ultrasound exploration revealed the presence of collections ranging in size from 27 to 50 mm, with an average of 34 mm. The ACR classification was as follows ACR5 in 3 cases, ACR4 in 11 cases including 3 cases of ACR4c, 3 cases of ACR4b and 5 cases of ACR4a, 22 cases of ACR3, ACR2 in 10 cases and ACR1 in 2 cases. The diagnosis of cancer was confirmed histologically in 6 cases, i.e. the 3 cases of ACR 5 and the 3 cases of ACR4c.

Discussion :

Ultrasound is a complementary examination to mammography, and is often the examination of choice and first diagnostic tool in women under 35 years of age and in the presence of inflammatory signs or intense mastodynia of  making mammography difficult at first.

It can reveal aspecific signs: skin thickening (greater than 3 mm); hyperechogenicity of fatty lobules related to oedema or galactophore dilatation with echogenic content (greater than 3 mm) [1]. On ultrasound, inflammatory mastitis of infectious origin appears as a hypoechoic lesion, generally rounded or oval, with or without irregular contours. Ultrasound transmission is moderate or good; the central internal echoes of a wall abscess are generally regular (mobile echoes) and partitions may appear. Most abscesses are surrounded by hypoechoic, oedematous tissue. Fistulous ducts appear as hypoechoic, tubular structures snaking through an indurated area [1].  In inflammatory mastitis of suspicious appearance, high-frequency probe studies of the skin can 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 [3]. Ultrasound can of course detect masses in 80% of cases, with lesions sometimes being multifocal or multicentric [4]. 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 [3]. Other less decisive signs can be identified, such as dilation of the vessels and lymphatics in 68% of cases, or pectoral involvement. Lastly, one of the essential pieces of information provided by ultrasound is a high-performance analysis of lymph node areas, not only in the axilla but also in the supra- and sub-clavicle and even in the internal mammary glands [3,4].

Conclusion:

Ultrasound, as a first-line examination of mastitis, has an important diagnostic value in the detection of cancer in its inflammatory form. 

Références :

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3.           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.

4.           Yang WT, Le-Petross HT, Macapinlac H, Carkaci S, Gonzalez-Angulo AM, Dawood S, et al. Inflammatory breast cancer: PET/CT, MRI, mammography, and sonography findings. Breast Cancer Res Treat.2008;109(3):417—26.