Diagnostic ultrasound ( PDFDrive )

796 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
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LT BR 1230 2B RAD
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RT AR 930 2B palp area
FIG. 21.54 Hyperechoic Fibrous Tissue Collections. Normal isolated collections of hyperechoic interlobular stromal ibrous tissue can cause
(A) mammographic nodules and masses, or (B) palpable ridges.
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B
FIG. 21.55 Hyperechoic Malignancies. The negative predictive value of purely and intensely hyperechoic tissue is essentially 100%. However,
collections of hyperechoic tissue should not contain any hypoechoic or isoechoic areas that are larger than normal ducts or terminal ductolobular
units (TDLUs). (A) Certain small, invasive carcinomas can appear with tiny hypoechoic central foci (arrow) surrounded by a very thick, echogenic
rim (*). Near-ield volume averaging or tangential imaging through the thick, echogenic rim of such lesions can make them falsely appear to be
purely hyperechoic. (B) In addition, hyperechoic masses with internal vascularity may also represent malignancy and should be sampled.
lobulations) and parallel orientation that is completely encompassed
by a thin, echogenic capsule. If a nodule its into one of
these three categories, it can be characterized as BI-RADS 3,
“probably benign.”
Hyperechoic Tissue
Purely hyperechoic tissue is oten normal interlobular stromal
ibrous tissue or fat, which can cause either palpable or mammographic
abnormalities (Fig. 21.54). To be considered benign,
the hyperechoic tissue should contain normal-sized ducts or
TDLUs without any isoechoic or hypoechoic structures larger
than normal ducts or lobules. Purely hyperechoic carcinomas
are exceedingly rare, but occasionally a carcinoma may have a
very small, hypoechoic central nidus and a very thick, echogenic
rim, and technical errors such as volume averaging or tangential
imaging through the rim can make the lesion falsely appear to
be purely hyperechoic (Fig. 21.55A).
It is important to correlate all hyperechoic masses with the
mammographic indings. Hyperechoic masses that appear radiolucent
on mammography are benign fat-containing masses, such
as lipoma, oil cysts, or fat necrosis. Hyperechoic masses seen
with a water density mass on mammography in the setting of
trauma could represent fat necrosis or hematoma, and follow-up
is warranted to ensure resolution. Biopsy of any hyperechoic mass
that has any suspicious mammographic or sonographic feature
should be performed. Similarly, although benign hyperechoic
masses such as angiolipoma or pseudoangiomatous stromal
hyperplasia can be vascular, any hyperechoic mass with increased