Diagnostic ultrasound ( PDFDrive )

CHAPTER 21 The Breast 787
TABLE 21.2 Comparison of Morphologic
and Histopathologic Features of Suspicious
Sonographic Findings
Morphologic Features
SURFACE
CHARACTERISTICS AND
MARGINS
Spiculation
Angular margins
Indistinct margin
Microlobulation
SHAPES
Irregular
Not parallel
Duct extension
INTERNAL
CHARACTERISTICS
Calciications
Acoustic shadowing
Hypoechogenicity
Histopathologic Features
“HARD” FINDINGS
Spiculation
Echogenic rim
Angular margins
Acoustic shadowing
MIXED FINDINGS
Hypoechogenicity
Not parallel
“SOFT” FINDINGS
Microlobulation
Duct extension
Microcalciications
FIG. 21.39 Indistinct Margins in Invasive Ductal Carcinoma, Grade
3. An indistinct margin refers to the inability to delineate the margin of
the breast mass. This feature, in combination with other suspicious
features including hypoechoic and not parallel appearance, make this
mass highly suspicious for malignancy.
Suspicious Findings
he suspicious sonographic features can be classiied into subgroups
by morphologic features or by histopathologic features
(Table 21.2).
Table 21.2 shows the suspicious indings listed by their
morphologic features: shape (irregular), margins (indistinct,
spiculation, angular margins, and microlobulations); orientation
(termed “not parallel” in ACR BI-RADS ultrasound lexicon 17 );
duct changes; and internal characteristics (acoustic shadowing,
hypoechoic echotexture, and calciications). Histopathologic
categories include “hard” indings that indicate the presence of
invasion of surrounding tissues (angular margins, spiculation,
thick echogenic rim, and acoustic shadowing); “sot” indings
that indicate the presence of DCIS components of tumor
(microlobulations, calciications, and duct changes); and mixed
indings that can be seen in association with either invasive or
DCIS components of tumor (hypoechoic echotexture and not
parallel orientation).
Sot suspicious indings help in three ways. First, sot indings
can help clinicians detect pure DCIS, which rarely develops hard
suspicious indings, and the most common breast carcinoma
usually contains DCIS components. Second, including sot
indings can help to detect and characterize the circumscribed
invasive duct carcinomas that contain both invasive and DCIS
components. In such cases, the new periphery of the lesion is
where the DCIS components are located. hus the surface
characteristics and shapes of the lesion are created by the DCIS
elements of the lesion, not by the centrally located invasive
components. Finally, the use of sot indings can aid in accurately
staging malignant breast lesions on sonography, because the DCIS
components of the lesion that extend into the surrounding tissues
for variable distances can be identiied only by sot indings.
Although sot indings do increase the sensitivity of the sonographic
algorithm for detecting malignant disease, they also
increase the false-positive rate, especially for lesions that contain
only sot indings. Lesions that demonstrate only sot indings
are most likely to be benign and include papillomas, ibroadenomas,
and FCC. However, given that the risk of malignancy for
solid masses that demonstrate only sot suspicious indings is
greater than 2%, it is still important that such lesions be characterized
as mildly suspicious (BI-RADS 4a) and that biopsy be
performed.
Indistinct Margins
“Indistinct margins” refers to the inability to distinguish any
portion of the margin of the mass from the surrounding tissue
(Fig. 21.39). his also includes masses that have an echogenic
rim, because the surrounding echogenic area prevents clear
demarcation of the mass’ margins.
Spiculation or Thick Echogenic Rim
Spiculation is a hard sonographic inding that corresponds to
invasion of surrounding tissues and a desmoplastic host response
to the lesion. Spiculation is a subcategory of the ACR BI-RADS
category “Margin–Not Circumscribed” 17 and is a mammographic
inding that can be directly applied to sonography (Fig. 21.40A).
When the spiculations are coarse, they manifest as alternating
hypoechoic and hyperechoic lines that radiate perpendicular to
the surface of the nodule; the hypoechoic components represent
either ingers of invasive tumor or DCIS components of tumor
extending into the surrounding tissues, and the hyperechoic
elements represent the interfaces between the spicules and surrounding
breast tissues (Fig. 21.40B). In most cases, however,
spicules are ine and manifest with only a single echogenicity.