Diagnostic ultrasound ( PDFDrive )

CHAPTER 21 The Breast 785
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FIG. 21.37 Inlamed or Infected Cyst. (A) Acutely inlamed or infected cysts demonstrate three indings: (1) abnormal uniform isoechoic wall
thickening (between arrows), (2) dependent debris (*), and (3) hyperemia of the thickened wall. (B) Supine and (C) upright images show the debris
(*), resembling sludge within a gallbladder, shifting to the dependent part of the cyst when the position of the patient is changed from supine to
upright or lateral decubitus position. Note the change in the position of the interface between the nondependent luid and the dependent debris
or pus (arrows).
in lateral decubitus or upright positions (Fig. 21.37B-C). However,
tumefactive sludge may be so viscous that it requires 5 minutes
or more to shit to the new dependent position. he hyperemic
vessels in the wall of inlamed cysts course in a direction parallel
to the cyst wall, in contrast to vessels that feed intracystic
malignancies, which tend to course perpendicular to the cyst
wall. hese indings indicate acute inlammation, which is
common in FCC, but do not necessarily indicate infection. Even
ater aspirating pus under ultrasound guidance, the clinician
cannot determine whether the cyst is infected or merely inlamed.
his requires Gram stain and culture. Many times, however, the
key to diferentiating inlammation from infection lies with the
clinical examination. Oten patients with infection will have
tenderness, erythema, and warmth overlying the area of clinical
concern.
Uniform wall thickening may also be seen in cysts with ibrotic
walls, but in such cases, there is no hyperemia or tenderness of
the thickened wall because cysts with ibrotic walls represent
the healed phase of acute inlammation. he luid and debris
within acutely inlamed cysts usually can be completely aspirated,
but the residually thickened cyst wall will persist. If the cyst was
not infected, usually the luid and debris do not reaccumulate,
and the residually thickened wall gradually resolves over a few
days. Because the sonographic appearances of acute inlammation
are so characteristic and do not raise questions about neoplasm,
we usually do not perform cytologic evaluation of the aspirated
cyst luid. Rather, if there is concern for infection, Gram stain
and culture are recommended. Oten patients will be provided
with empiric antibiotic therapy while awaiting culture results.
Solid Masses
Initially, sonographic studies reported substantial overlap between
the features of benign and malignant solid nodules that prevented
a clear distinction to be made. hese studies were performed
with older, lower-frequency, lower-resolution equipment and
generally assessed only single sonographic indings. Since then,
the approach to characterizing solid nodules has substantially
improved.
he key to developing a successful algorithm for characterizing
solid nodules is having realistic goals. Distinguishing all benign
from all malignant solid nodules is challenging, and therefore
a more realistic goal is to identify a subpopulation of all solid