Diagnostic ultrasound ( PDFDrive )

780 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
A
C
D
B
FIG. 21.28 Eggshell Calciication. (A) Eggshell calciications are mammographic indings that are deinitively benign. (B) Dense eggshell calciications
cause acoustic shadowing on ultrasound. (C) Punctate calciications conined to the thin echogenic cysts walls can be thought of as incomplete
eggshell calciications and therefore are benign. (D) Nondependent and nonmobile punctate calciications within the interior of the cyst are nonspeciic
and can be associated with papillary apocrine metaplasia (PAM) or ductal carcinoma in situ (DCIS).
FIG. 21.29 Clustered Macrocysts. Thin, echogenic septations within
cysts are not suspicious. Such septations represent residual walls of
cystically dilated acini within a single terminal ductolobular unit (TDLU)
and can be thought of as clusters of simple cysts.
Acorn cysts have a crescentic, eccentrically thickened wall
caused by PAM that does not completely ill the cyst (see Fig.
21.31B). Unlike the echogenic crescent within cysts that contain
fat-luid levels, the echogenic crescent caused by PAM does not
shit within the cyst when the patient changes position,
regardless of duration (see Fig. 21.31C and D). In these cases
the normal, thin, echogenic outer cyst wall is preserved along
the entire thickened wall, and there is no vascular stalk (see Fig.
21.31E). It is important to conirm that none of the internal
components is vascular or solid because this may be suggestive
of a complex cystic and solid mass rather than an acorn cyst
(see next section). If there is any question as to whether this
represents a true mural nodule, biopsy should be performed. If
no suspicious features are identiied, then this can be followed
and classiied as BI-RADS 3.
he algorithm used for evaluation of nonsimple cysts has
been derived from the mammographic and solid nodule algorithms.
he BI-RADS lexicon should be used to characterize the
mass. he presence of even a single suspicious inding requires
exclusion from the BI-RADS 2 category, and possibly the BI-RADS
3 category. Although every efort should be made to characterize
as many nonsimple cysts as BI-RADS 2 as possible, they must
meet strict criteria before they can be characterized as such.
Complex Cystic and Solid Masses
Complex cystic and solid masses contain both solid and cystic
components. hey may have thick and irregular walls, mural
nodules, thick septations, and internal blood low (Fig. 21.32).
hese complex masses are at increased risk of containing papillomas
or carcinomas such as DCIS, papillary carcinoma, or
iniltrating ductal carcinoma, with or without necrosis. Since it
is not always easy to determine whether the internal material is