Non-mass-like lesions on breast ultrasonography: a systematic review

Abstract

This article reviews various non-mass-like ultrasonography (US) findings of the breast and the sonographic-pathologic correlation with Doppler techniques, elastography, and MRI. High-resolution US allows for identification of small, clinically occult non-mass-like US findings. Ductal carcinoma in situ and invasive lobular carcinoma usually manifest as a non-mass-like lesion on US. It is useful to classify non-mass-like lesions on US in a similar manner to the classification of non-mass-like enhancement on MRI.

Non-mass lesions on screening breast ultrasound

“…There have been a few studies regarding NMLs on breast US [3][4][5][6]13] and all of these studies had different inclusion criteria. Morishima et al [13] reported the sonographic characteristics of breast cancer that showed NMLs.…”

“…DCIS lesions have been reported to be identified as NMLs of ductal or non-ductal pattern with or without echogenic spots corresponding to the mammographic findings [7,8] and Shin et al [9] reported that 17 of 106 DCIS lesions (16%) were shown as NML on screening detected DCIS. ILC also may not form a mass because it is composed of non-cohesive cells individually dispersed or arranged in a single-file linear pattern within fibrous stroma [4,10]. In Selinko et al series [12], 15% of ILC were described as an ill-defined area of altered, hypoechoic, inhomogeneous echotexture without identifiable margins and without frank shadowing.…”

“…With the use of high-resolution ultrasound (US) equipment and the recent introduction of supplementary screening breast US in a population with dense breasts and an elevated risk of breast cancer, the hypoechoic nonmass lesions (NML) that do not meet the criteria of a mass defined by the American College of Radiology Breast Imaging Reporting And Data System (ACR BI-RADS) lexicon [1] are sometimes encountered [2][3][4]. It has been reported that these lesions on US can reflect a wide spectrum of pathologic changes such as fibrocystic change, fibrosis, mastitis, ductal carcinoma in situ (DCIS), invasive lobular carcinoma (ILC), or invasive ductal carcinoma (IDC) [3][4][5][6][7][8][9][10][11][12].…”

“…It has been reported that these lesions on US can reflect a wide spectrum of pathologic changes such as fibrocystic change, fibrosis, mastitis, ductal carcinoma in situ (DCIS), invasive lobular carcinoma (ILC), or invasive ductal carcinoma (IDC) [3][4][5][6][7][8][9][10][11][12]. However, these NMLs are not included in the BI-RADS lexicon for breast US [1].…”

Non-mass-like lesions on breast ultrasound: classification and correlation with histology

“…Not only malignant lesions, but also non-malignant lesions can also appear as non-mass-like lesions, such as adenosis, intraductal papilloma and plasma cell mastitis. Some studies classified the "hypoechoic area" into ductal hypoechoic area and nonductal hypoechoic area according to whether they describe patterns reminiscent of the milk duct system or those reminiscent of glandular tissue [13]. However, this classification was derived from MRI and it is not suitable for US findings.…”