Chapter Ⅱ　Ultrasound Diagnosis of Breast Cancer

Chapter Ⅱ　Ultrasound Diagnosis of Breast Cancer

Breast disease，a common multiple disease in women，most of which are breast cancer.In recent years，the incidence of breast cancer has shown a gradual increase trend in China.It has seriously threatened the life and health of women.Early diagnosis and treatment of breast cancer can directly affect the selection，outcome and prognosis of treatment programs.

［Etiology］

The etiology of breast cancer is not clear.Its occurrence and development are due to the joint action of various factors inside and outside the body.It is generally accepted that the following related factors are relevant：breast cancer has obvious family genetic tendency，past breast disease history，correlation with endogenous and exogenous hormones，environmental factors，lifestyle and other risk factors.

［Pathology］

The tissue and morphological types of breast cancer are complex and diverse.In China，the following pathological types are mostly adopted：

1.Non-invasive cancers mainly include ductal carcinoma in situ（cancer cells do not break through ductal basement membrane.According to histological changes，it is divided into comedo carcinoma and non-comedo ductal carcinoma in situ），lobular carcinoma in situ（cancer cells do not break through distal mammary duct or acinar basement membrane）and papilla eczema-like breast carcinoma（except those accompanied with invasive carcinoma）.The prognosis of this type is better.

2.Invasive non-specific cancers mainly include invasive ductal carcinoma，invasive lobular carcinoma，scirrhous carcinoma，carcinoma simplex，adenocarcinoma，medullary carcinoma（no large amount of lymphocyte infiltration）.This type is the most common type of breast carcinoma.

3.Invasive special cancers mainly include medullary carcinoma（with large amount of lymphocyte infiltration），papillary carcinoma，tubular carcinoma，mucinous adenocarcinoma，paget's disease，inflammatory breast cancer，etc.

4.Other rare cancers：lymphoma，metastatic tumor，leukemia，etc.

［Indications for ultrasound examination］

Ultrasound，one of the imaging examination methods for breast diseases，has the advantages of no radiation，high diagnostic accuracy，convenience and quickness，and easy follow-up review.Ultrasound has an important effect in clinical diagnosis and treatment.

Indications for breast ultrasound examination：clinically，there are breast-related symptoms and signs，location and diagnosis of breast masses，breast pain and nipple discharge；other imaging examinations found that breast abnormalities or diagnosis is difficult；follow-up of breast lesions；preoperative and postoperative evaluation of breast surgery.

［Methods of breast ultrasound examination］

The patient takes a recumbent position，bilateral breasts are fully exposed，and a high-frequency probe with a frequency of 5-14 MHz is applied to comprehensively scan the four quadrants and areola regions of the breast to avoid missed scanning.After the lesion is found，the lesion is observed in multiple sections，and axillary lymph nodes also need to be observed.For conditional patients，techniques such as elastography and contrast-enhanced contrast imaging can be used to obtain more diagnostic information.

［Ultrasonography of Breast Cancer］

1.The edge of the mass：there is no clear boundary between the fuzzy mass and the surrounding tissues；The edge of an angled mass can form a sharp angle，usually an acute angle；The edge of the subdivision lobe mass can form gear-like undulations.Burrs can project sharp thin lines from the edge of the mass.

Fig.A 1　Edge burr and angle

Fig.A 2　Edge subdivision lobe

Fig.A 3　Edge fog

Fig.A 4　Edge angle

2.The shape of the mass is irregular，it is neither oval nor round.

Fig.B 1　The shape is irregular，with subdivision lobe.

Fig.B 2　The shape is irregular

Fig.B 3　The shape is irregular

3.The orientation of the mass is not parallel，the long axis of the lesion is not growing along the skin line，that is，the height is greater than the width，and the ratio of horizontal width to vertical height is usually greater than 1.When defining the course direction of a mass，the longest diameter line of the mass needs to be observed.

Fig.C 1　Lesion：the ratio of horizontal width to vertical height is usually greater than 1.

Fig.C 2　Longitudinal growth of tumor.

4.Comparison between the echo of mass and that of fat layer.Breast cancer is generally hypoechoic，partially isoechoic or cystic-solid mixed echo.

Fig.D 1　Hypoechoic lesion

Fig.D 2　Isoechoic lesion

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Fig.D 3　Mixed echo focus

5.The posterior echo is related to the internal tissue components of the tumor.Most of the posterior echo is weakened，and some of the posterior echo of breast cancer can be enhanced or have no obvious change.

Fig.E 1　Attenuation of echo posterior

Fig.E 2　Increase of posterior echo

Fig.E 3　Change of posterior echo is not obvious.

6.Calcification：the location of calcification is emphasized inside and outside the mass or inside and outside the catheter.Calcification less than 1mm is microcalcification in breast cancer.

Fig.F 1　Fine calcification in lesion

Fig.F 2　Fine calcification in lesion

Fig.F 3　Fine calcification in lesion

7.Structural distortion：tumor infiltrates or oppresses surrounding tissues，damages or pulls surrounding tissues and cooper ligaments.Skin changes：edema and thickening of skin or“orange peel”or“dimple”changes caused by pulling.

Fig.G 1　Disruption and distortion

Fig.G 2　Distorted peripheral

Fig.G 3　Skin involvement of gland structures of lesions

8.Axillary lymph node metastasis：lymph node enlargement，cortical thickening，lymph hilum deviation or disappearance，metastatic lymph node blood flow mostly shows peripheral or mixed blood flow.

Fig.H 1　Cortical thickening，lymph node portal deviation

Fig.H 2　Abundant blood flow

Fig.H 3　Lymph hilum disappearance

9.CDFI breast cancer internal blood flow is mostly grade Ⅱ-Ⅲ，blood flow is relatively rich，and perforator blood flow can be seen.

Fig.I1　Alder grade Ⅲ

Fig.I1　Alder grade Ⅲ

Fig.I3　Alder grade Ⅱ

Fig.I4　Alder grade Ⅱ

［Elastic imaging］

There are two types of ultrasonic elastic imaging.They include strain elastography（SE）and shear wave elastography（SWE）.Elastic imaging is performed for elastic differences of different tissues.Strain elastography can evaluate the deformation of tissues under external pressure.Shear wave elastography is a quantitative technique，it can obtain hardness values.In general，we think that the hardness of most tissues in malignant tumors is relatively high.At present，due to different settings of various manufacturers'instruments，elastography can not form a unified diagnostic standard.

［Contrast-enhanced ultrasound］

Contrast-enhanced ultrasound（CEUS）is one of the new ultrasound technologies in recent years.A large number of studies have confirmed that there are differences in vascular pathological characteristics between benign and malignant breast tumors，which provides the possibility for the diagnosis of breast cancer by contrast-enhanced ultrasound.Contrast-enhanced ultrasound manifestations of breast malignant tumors are mainly：homogeneous or inhomogeneous high enhancement.After enhancement，the shape of the lesion is irregular and the edge is unclear，accompanied by feeding vessel sign or bunching sign.At present，there is a dispute over the use of contrast-enhanced ultrasound in the diagnosis and treatment of breast diseases.With the continuous development and optimization of sub-technology，it may be gradually improved.