Ultrasound differential diagnosis of benign and malignant cystic lesions of the breast Breast cysts include simple cysts DD are commonly seen in women over 40 years of age at the time of ultrasound examination. Simple cysts are not potentially malignant, but cystic solid masses can create an ambiguous diagnosis [1,2].Berg et al. described a variety of different benign lesions, and complex cysts in 23% of the patients they studied were confirmed to be malignant lesions. Intracapsular carcinoma of the breast is a rare entity, accounting for 0,3-2,0% of all breast cancers, and the solid portion is already larger at the time of diagnosis [3]. We tried to classify cystic lesions of the breast according to ultrasound features and associated pathological findings. The typical features of benign and malignant cystic masses are evaluated and the patient is managed appropriately according to the ultrasound presentation. Classification of cystic breast lesions 1. simple cyst (type I): an echogenic mass with no echogenic light spot, clear borders, and posterior echogenic enhancement; 2. clustered cyst (type II): a clustered echogenic mass with no separated solid components; 3. thin septal cyst (type III): cystic septal thickness <0,5mm; 4. composite cyst (type IV): according to the American Radiological Society Breast Imaging Reporting and Data System (BI-RADS) [4] defined as: including fluid and debris fluid planes or debris floating echogenicity within the cystic lesion. 5. thick wall/thick septum or nodular cyst (type V): septum, wall thickness >0.5 mm or mixed cystic-solid mass with at least 50% solid component of cystic; 6. complex solid cystic mass (type VI): primary substantial lesion with focal eccentric liquefaction zone II. results Figure 2: Classification, sampling method, malignancy rate of 175 cystic lesions Figure 3: 175 cystic lesions Ultrasound presentation versus pathologic findings Figure 4: Ultrasound presentation and malignancy rate of 80 cystic masses with solid components III. Discussion Breast cysts are common in women over 40 years of age and most are considered benign (BI-RADS category 2). type I lesions, including simple cysts, do not require intervention if the patient is asymptomatic because such cysts are not potentially malignant. If the patient is symptomatic, such as painful or palpable, they are often larger cysts and may be selectively aspirated. Because Type II lesions include clustered cysts with no solid component, they are considered benign and routine follow-up examinations are recommended. Berg considered clustered microcysts without a solid component to be likely benign, and based on follow-up of 79 lesions, none were confirmed to be malignant. Such lesions are often associated with parietal pulp-secreting glandular chemosis or fibrocystic degeneration, which is the early stage of cystic degeneration and results in the formation of microcysts due to parietal pulp secretion, increased secretion, increased pressure in the glandular ducts, and unfolding and fusion of adjacent glands. The larger typeIII thin septal cysts represent a continuation of parietal pulp secretory gland chemosis to cysts, which is the fusion of glands. In our study the sonogram was a clustered cyst, indicating a cyst or fibrocystic change, with no malignancy on follow-up. Although we determined that TypeIV cysts were homogeneous hypoechoic complex lesions, in other respects applying the criteria of simple cysts with slender walls and debris fluid flattening, 21/35 (60%) were confirmed as abscesses. When abscesses are clinically suspected, imaging is performed or fluid examination is performed and I perform aspiration to confirm, followed by a course of antibiotics or surgical drainage. venta et al. series] 308 composite cysts, of which 0, 3% were confirmed as malignant; however, they are usually treated for regular imaging follow-up, as they are likely to be benign lesions. In a series of ultrasound surveillance, Buchberger et al [10] found 133 such lesions to be benign, and Kolb et al found none of the 126 lesions to be malignant. Symptomatic compound cysts should be managed according to clinical signs and aspiration is commonly applied in the differential diagnosis, which includes abscesses, hematomas, fat necrosis, and cumulus cysts. TypeV lesions with thick-walled, thick-spaced, or nodular cystic masses are considered potentially malignant and a tissue biopsy should be performed. 35% of cystic masses with thick walls or thick septa were found to be malignant by Berg et al. 86% of these were highly differentiated ductal infiltrating carcinomas, and 33% showed clear borders on ultrasound. For specific diagnosis in TypeV cases, wall/spacer or nodal core needle biopsy is preferred over aspiration because the cystic component can be necrotic or acellular. Of the 27 type V lesions in our study, 7 (25, 9%) were confirmed to be malignant, 5 (71%) were ductal infiltrating carcinomas and 2 were papillary carcinomas. Abscesses, apocrine glandular metaplasia, inflamed or ruptured abscesses or ducts, and hematomas may present as thick-walled cysts. Fat necrosis may present as thick-walled cystic lesions or composite cysts and solid masses, and in Type VI complex solid cystic masses, eccentric cystic foci may consist of dilated ducts, glandular vesicles, or necrosis. first described by Jackson et al. as rare eccentric cystic foci in fibroadenomas. Fibroadenoma-like structures with cystic foci should be considered lobar tumors, although such tumors are rare, and Liberman et al. suggested that tumors with fluid foci are often malignant lobar tumors. According to Berg et al, malignant tumors with the presence of eccentric cystic foci are not specifically discriminated between highly and poorly differentiated invasive ductal carcinomas. In our study, there was no difference in the degree of differentiation of cells according to Type VI complex solid cystic masses. However, complex solid cystic masses were confirmed as saprophytic carcinomas, malignant lobulated tumors, and mucinous carcinomas, represented as malignant masses with cystic components. Papillary carcinoma is seen in cystic masses of the breast. Cystic malignant masses have a better prognosis than other forms of breast cancer, but are usually bloody when the internal fluid is aspirated. The hypothesis of having a cystic component malignant mass follows several aspects of pilot studies, the chance of cancer infiltrating the cystic disease area and the chance of highly differentiated malignancy with cystic degeneration. Papilloma or papillary carcinoma is seen in cystic breast masses. Intracapsular papillary carcinoma accounts for 0, 3% of breast cancers. Hong et al [20] considered (9%) of the masses ultrasonographically described as ovoid and well-defined as malignant. In our study, of 80 cystic masses with solid components, 40 (50%) were confirmed as malignant and 16/80 (20%) were confirmed as malignant with limited masses detected by ultrasound. The relatively high rate of malignancy may be due to the exclusion of symptomatic patients and the inclusion of seemingly benign malignant masses of various pathological types (e.g., saprophytic carcinoma, papillary carcinoma, mucinous carcinoma, and malignant lobar tumors). In our series, 97 lesions were followed up and classified as cystic masses without solid components, and one case was confirmed as an invasive ductal carcinoma at 36 months follow-up after examination. However, in the ultrasound follow-up, this lesion separated from the cyst to produce a solid mass of 5 mm. This study has several limitations in that the selection of these cases was retrospectively confirmed by disease, static imaging analysis, although static imaging is a common method for retrospectively analyzing clinical breast sonograms, with only a few cases of each classification. This approach needs to be confirmed by multiple medical centers. However, it is worth noting that the differential diagnosis of cystic masses is evaluated based on benign and malignant ultrasound presentation with pathological correlation, as well as patient care based on the type of breast mass subsequently recommended. IV.CONCLUSION: Because in our study ultrasonographic exploration of simple cysts (Type I), clustered cysts (Type II), and thin septal cysts (Type III) were benign, interventional treatment was not necessary, but routine annual follow-up examinations were necessary. Symptomatic compound cysts (Type IV) should be treated with aspiration cytology or according to clinical symptoms. Thick-walled, thick-spaced or nodular cystic masses (Type V) and complex solid cystic masses (Type VI) should undergo histopathologic biopsy for pathologic confirmation, although sometimes these are ovoid and well-defined lesions.