Mammary tumors

Breast tumors are characterized by the presence of a delimited formation or zone with a violation of the normal echostructure of the breast. The nature and type of growth of the volumetric formation are determined based on the following features: structure and nature of contours; relationship with surrounding structures; echogenicity and type of internal structure; acoustic effects observed behind the tumor; vascularization.

Expansive growth implies smooth contours. The tumor does not destroy surrounding tissues, but only pushes and compresses them. With infiltrative growth, the contours of the formation are often unclear and uneven. It can be difficult to distinguish between the tumor and surrounding tissues.

The tumor may have its own anatomical capsule or a pseudocapsule formed by compressed or secondarily altered surrounding tissues.

Tumor echogenicity may vary, but malignant tumors are more characterized by a decrease in overall echogenicity and heterogeneity of the internal structure.

Acoustic effects in mammary gland tumors vary from slight enhancement to the appearance of an acoustic shadow behind the tumor. An acoustic shadow is detected behind 30-65% of malignant tumors.

The ratio of the transverse diameter of the tumor (P) to the anterior-posterior diameter (APD) can be useful for determining the nature of the formation. When the transverse diameter (parallel to the skin) is greater than the anterior-posterior diameter (P/APD > 1), i.e. there is a horizontal orientation, the pathological process is most often benign. Predominance of the anterior-posterior size (P/APD < 1), i.e. vertical orientation, is more common in malignant tumors. Some authors believe that a more successful criterion for assessing the benignity or malignancy of a tumor is to compare the P/APD ratio with the number 1.4. In particular, up to 100% of cancers have a P/APD ratio < 1.4, while benign pathological processes are characterized by P/APD > 1.4. Thus, the P/APD index should be considered as one of the criteria characterizing a tumor.

Benign breast tumors

Fibroadenomas

Fibroadenoma accounts for 95% of all benign tumors of the mammary glands. Most often, fibroadenoma of the mammary gland symptoms are determined in women from 15 to 40 years old. During this period, the occurrence of fibroadenoma of the mammary gland is the result of abnormal development of glandular tissue. Fibroadenoma, which occurs and develops in a pregnant and lactating woman, is called lactation fibroadenoma. Long-existing fibroadenomas undergo involution, hyalinization and calcification, which is manifested by heterogeneity of the echostructure with the presence of hyperechoic inclusions. The size of these inclusions can be very small or occupy almost the entire formation. Since the formation of fibroadenoma is associated with estrogen stimulation, new development and an increase in its size can occur in the premenopausal and menopausal period against the background of hormone replacement therapy.

As a rule, fibroadenoma, its symptoms are a single formation. In 10-20% of fibroadenomas are multiple, often bilateral. In about half of the cases, the tumor is located in the upper outer quadrant. The size of fibroadenoma usually does not exceed 2-3 cm. Its shape is often oval, with the predominance of the long axis P over the short axis PZ. The ratio P/PZ> 1.4 occurs in 86% of fibroadenomas.

Echographically, fibroadenoma is a solid formation with clear, even contours. When compressed by a sensor, a "slipping" symptom is noted - a displacement of the tumor in the surrounding tissues, which confirms the expanding nature of fibroadenoma growth. Depending on the size of the fibroadenoma, the ultrasound picture has its own characteristics. So, with sizes up to 1 cm, a regular round shape, a homogeneous internal structure of reduced echogenicity are noted. The contours are even, clear or unclear. A hyperechoic rim along the periphery is noted in about 50% of cases. Fibroadenoma of the mammary gland symptoms - more than 2 cm often have an irregular round shape, a clear, even or uneven contour. The larger the size and duration of fibroadenoma, the more often a hyperechoic rim is determined, caused by degeneration of the surrounding tissues. In more than half of the cases, heterogeneity of the internal structure is noted against the background of a general decrease in echogenicity. In 25% of cases, micro- and even macrocalcifications are observed. Fluid-containing inclusions are often detected. A fibroadenoma larger than 6 cm is called giant. This tumor is characterized by slow development and the appearance of large coral-shaped petrifications with a pronounced acoustic shadow. According to echogenicity, fibroadenoma can be hypoechoic, isoechoic, and hyperechoic. The detection of fibroadenomas using echography depends on the echogenicity of surrounding tissues.

Hypoechoic fibroadenoma is poorly differentiated in the mammary gland with an increased content of adipose tissue. At the same time, a well-demarcated and prominent hypo- or isoechoic fat lobule against the background of surrounding tissues can imitate fibroadenoma.

A circumscribed area of fibrosis or sclerosing nodular adenosis may also mimic fibroadenoma.

Ultrasound imaging of fibroadenoma of the mammary gland can mask, especially in young patients, a well-demarcated malignant tumor (usually medullary cancer).

Degenerative changes in the structure of fibroadenoma in the form of acoustic shadows behind calcifications, heterogeneity of the internal structure, and uneven contours can imitate the symptoms of breast cancer in older women.

Fibroadenomas with large calcifications are well differentiated by X-ray mammography. In the absence of calcifications, X-ray mammography cannot differentiate the symptoms of fibroadenoma of the mammary gland from a cyst.

An important diagnostic criterion in echography may be the assessment of tumor vascularization. According to Chorsevani and Morishima, vascularization is determined in approximately 36.0% of fibroadenomas (the average age of women was 38.5 years). The vessels identified were located along the periphery of the nodes in 67.0-81.1%, throughout the node - in 13.6%, uneven distribution of vessels was detected in only one case (4.6%).

Cosgrov's work states that the detection of vessels in previously non-vascularized fibroadenomas using color Doppler mapping allows one to suspect malignancy.

Phyllodes tumor

This is a rare fibroepithelial tumor of the mammary gland. In cross-section it resembles folded cabbage leaves. The tumor most often occurs at the age of 50-60 years. Being benign, the tumor in 10% of cases can degenerate into sarcoma. Differentiation of benign or malignant nature of the lesion is possible only histologically. Echographic picture is characterized by visualization of solid hypoechoic well-delimited formation without additional acoustic effects. The structure of the tumor can be heterogeneous due to cystic slit-like cavities.

Lipoma

True lipomas are a node of mature adipose tissue surrounded by a connective tissue capsule. When palpated, a soft, mobile formation is detected in the mammary gland. The ultrasound picture of a lipoma resembles adipose tissue of the mammary gland - hypoechoic, homogeneous, compressible. In the presence of fibrous inclusions, the structure of the lipoma is less

Homogeneous, with hyperechoic inclusions, a hyperechoic rim may be detected. Lipoma can be difficult to isolate in the mammary gland with an increased content of fatty tissue. During echography, lipoma must be differentiated from fibroadenoma, with a very contrasting fat lobule or other fatty inclusions.

Adenolipoma, fibroadenolipoma are a variant of fibroadenoma and represent an encapsulated tumor consisting of fatty, fibrous tissue and epithelial structures. Adenolipomas can reach large sizes. In echography, adenolipomas have a heterogeneous structure with hypo- and hyperechoic inclusions.

Fibroangiolipoma can be very echogenic. In elderly women, a transparent formation in a dense fibrous capsule is detected. The absence of a capsule does not allow differentiating the lipoma from the surrounding fatty tissue. The tumor can reach large sizes.

Hamartoma

Hamartoma is a rare benign tumor of the mammary gland. It can be located both in the gland itself and at a distance from it. The ultrasound image of hamartoma is very variable and depends on the amount of fat and fibroglandular tissue in the form of hypoechoic and echogenic areas. The effect of distal pseudoenhancement or attenuation is determined depending on the structure of the tumor. X-ray mammography reveals a well-demarcated encapsulated formation with a heterogeneous structure.

Papilloma

Papillomatosis is a neoplastic papillary growth within a milk duct. These papillary growths are benign proliferations of some cells of the ductal epithelium. They most often occur at the age of 40-45 years as a single inclusion within a terminal duct or in the milk sinus. Most solitary intraductal papillomas are benign. Solitary intraductal papillomas appear as masses that are difficult to differentiate from fibroadenoma. They are rarely larger than 1 cm.

The ultrasound image of intraductal papilloma can be of four types:

1. intraductal;
2. intracystic;
3. solid;
4. specific (multi-cavity and speckled image).

The ultrasound image of the intraductal type of papilloma can be in the form of an isolated expansion of the duct or a solid formation of a round shape, of varying echogenicity, without the effect of distal attenuation against the background of an isolated expansion of the duct.

The intracystic type can be represented by an ultrasound image of a cyst with solid inclusions along the inner contour. The solid component can be of different sizes and echogenicity.

The solid type is characterized by the presence of a small solid structure (maximum size 9 mm) with a connecting or closely located dilated milk duct. Most solid formations have posterior enhancement; there is never an acoustic shadow. High P/PZ ratios are characteristic.

Diffuse intraductal papillomatosis is characteristic of lesions of the terminal, peripheral milk ducts. Being a disease of young women, it has a second name - juvenile papillomatosis. In 40% of cases, it is accompanied by atypical hyperplasia of epithelial cells of a suspicious histological nature. That is why diffuse papillomatosis has a high risk of developing breast cancer. Echographic picture of juvenile papillomatosis

Characterized by the presence of a poorly delimited heterogeneous mass without the effect of distal weakening, with small anechoic areas at the edges or around the formation. During ultrasound examination, it is necessary to evaluate the evenness and clarity of both the outer and inner contours, and if cystic expansion is detected, the agitation of the contents. Mammography is not informative. Galactography is the main method for visualizing intraductal formations. By introducing contrast, it is possible to detect not only obstruction, but also a very small defect in the duct wall. There are data on echogalactography with ultrasound evaluation of contrasted ducts.

Sclerosis of glandular tissue (sclerosing adenosis)

Tissue sclerosis usually accompanies involutional processes and is a variant of glandular degeneration. The ultrasound picture is rather non-specific. Most often, hyperechoic structures or their clusters are determined, behind which an acoustic shadow of varying intensity is detected. The posterior wall and underlying structures are not differentiated. The ultrasound image of sclerotic tissues can be characterized only by an acoustic shadow of irregular shape. The risk of missing a malignant process located in the acoustic shadow zone makes it necessary to perform a biopsy and morphological verification of the process.

Steatonecrosis

This is a rare lesion of the mammary glands, which usually occurs in obese elderly women. Being the result of trauma to the mammary gland, steatonecrosis has no specific histological picture. With steatonecrosis, compactions of the mammary gland may occur due to sclerosing adenosis, fibrous scars, chocolate cysts with pronounced calcification. These changes can exist for years or spontaneously regress. Usually, steatonecrosis is located in the subcutaneous or retronipple area. With a superficial location, steatonecrosis can cause fixation of the skin, retroposition and retraction of the nipple. Palpation of the steatonecrosis zone reveals a small hard nodule with fuzzy contours. The ultrasound picture is varied. Necrotic fat can be defined as a complex of fluid-containing masses, as an irregularly shaped hypoechoic or hyperechoic formation with a distal acoustic shadow. Changes in surrounding tissues may be expressed as disruption of normal skin orientation, contraction of Cooper's ligaments. Differential diagnosis is made with hyperplastic breast cancer, radial scars, hyperplastic fibrosis, or residual abscess and hematoma. Similar changes in the structure of the mammary gland are noted after biopsy and other types of invasive interventions.

Rare benign changes in the mammary gland

A number of rare breast diseases have very non-specific ultrasound and mammographic features and require mandatory biopsy to establish a diagnosis.

Leiomyoma

The occurrence of this benign tumor is a consequence of underdevelopment of the smooth muscles of the mammary gland. Mammographic and ultrasound images are nonspecific. On echograms, leiomyoma is visualized as a solid, well-demarcated formation with a homogeneous internal structure.

Retro-nipple adenoma

Retro-nipple adenoma is a benign proliferative disease of the nipple. It is characterized by smoothing, retraction, and inversion of the nipple due to the formation located in the retro-nipple region. A nipple abrasion suggests a clinical diagnosis of a malignant lesion (Paget's disease) even before a biopsy. Ultrasound and mammographic data do not allow differentiating this benign tumor from its malignant counterpart.

Diabetic fibrosis

This breast lesion may occur in patients with diabetes. Palpation reveals hard, lumpy nodes that are not fused with the surrounding tissues. Echography reveals pronounced acoustic shadows behind the superficial parts of the breast, masking the underlying tissues. Breast cancer demonstrates non-specific diffuse darkening. Puncture biopsy is inappropriate due to the high density of the palpable masses. This does not allow the needle to collect enough material to make a diagnosis.