2.2　Mucinous Adenocarcinoma of Breast

2.2　Mucinous Adenocarcinoma of Breast

Mucinous adenocarcinoma of breast is a rare type of breast cancer.Microscopically，cancer cells produce a large amount of mucus，which can be observed.Cells can float in mucilage and be round or polygonal.It can be divided into simple type and mixed type.Clinically，the growth of mass is slow.About half of them show swelling growth and the texture is soft.Simple ultrasound shows isoechoic lesions with regular shape，clear boundary and posterior echo enhancement；most of the mixed ultrasound features are breast malignant tumors.

Case 13：female，47 years old，has been found with a left breast mass for more than 1 year，with a marked increase of 1 month.Specialized examination：The upper quadrant of the left breast can touch the mass，which is hard，with unclear boundary and poor mobility.

Fig.A　Longitudinal and transverse sections，equiechoic lesions，regular in shape，clear in boundary，shallow lobulated at local edge，slightly enhances in posterior echo

Fig.B　Alder grade 1

Fig.C　RI：0.67

Fig.D　CEUS 25S：Uneven high enhancement lesion，scope is slightly increases

Fig.E　CEUS 40S：After enlargement of lesion de
creases，unevenlow enhancement

Fig.F　The time intensity curve shows that the focus is enhanced before the surrounding tissues，and the enhancement mode is high enhancement，and the enhancement peak value is higher than the surrounding tissues

Analysis and differential diagnosis：Left breast of middle-aged woman touches hard mass.Ultrasonography：Isoechoic lesion with regular shape，clear boundary，posterior echo enhancement，punctate blood flow signals around the lesion，Alder grade 2.Contrast-enhanced ultrasound shows that the focus is enhanced prior to the surrounding tissues，the enhancement mode is high enhancement，and the enhancement form is uneven enhancement.After enhancement，the focus shape is regular and the boundary is clear.No matter two-dimensional ultrasound or contrast-enhanced ultrasound，this lesion is regular in shape，clear in boundary，and no obvious calcification is found in the solid.It is easily misdiagnosed as benign fibroadenoma.Fibroadenoma has obvious capsule and internal echo is mostly hypoechoic.(https://www.daowen.com)

Pathological results：Mucinous adenocarcinoma is supported.

Case 14：female，51 years old，has been found right breast mass for more than 1 month.Specialized examination：The right breast areola area may touch the mass，with hard quality，unclear boundary and poor mobility.

Fig.A Maximum diameter section，moderate slight

Fig.B　Transverse section，regular shape，clear
lowecholesion boundary

Fig.C　Alder grade 2，the posterior echo is enhanced

Fig.D　RI：0.63

Fig.E　The elasticity score is 4 points

Analysis and differential diagnosis：Left breast of middle-aged and elderly women touches hard mass.Ultrasonography：Moderate and slightly hypoechoic lesion with regular shape，clear boundary，enhanced posterior echo，flake shape blood flow signal visible at periphery of lesion，Alder grade 2，elasticity score：4.The shape of the lesion is regular，the boundary is clear，and no obvious calcification is found in the solid.It is the same as the previous case and is easily misdiagnosed as benign fibroadenoma.However，the focus has no obvious capsule echo，elasticity and hardness.During the first visit，the patient should be advised to take active measures to avoid delaying the illness.

Pathological results：It supports most mucinous adenocarcinoma components.