Diagnostic ultrasound ( PDFDrive )

CHAPTER 10 The Prostate and Transrectal Ultrasound 405
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A B C
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E
F
G H I
FIG. 10.17 Prostate Cancer: Other Appearances. (A) Almost isoechoic, impalpable nonvascular cancer. Digital rectal examination (DRE)
indings were normal; prostate-speciic antigen (PSA), 6.08 ng/mL with 12% free/total ratio. Transrectal ultrasound (TRUS) is only mildly suspicious
for cancer at left (arrow). Biopsy showed isoechoic ultrasonically undetectable, Gleason 7/10 cancer in the right side involving 25% of the tissue.
On the left, where there is a visible lesion (arrow), the biopsy was only 15% cancer. This highlights the need to do both systematic and targeted
biopsy. (B) Power Doppler shows almost no detectable signal despite extensive bilateral cancer. Only about 80% of cancers demonstrate
increased vascularity. The strong Doppler color signal anteriorly is all artifactual (A), from calciication. (C) Extensive cancer with “starry sky”
appearance caused by comedonecrosis in the tumor. The malignant nodule extends across the entire peripheral zone (between cursors). On the
right, the calciied clumps are normal corpora amylacea (arrowhead). On the left, the densities have a different character: small, more scattered,
round, and very echogenic, and will “twinkle” on probe movement (arrows). These are highly suggestive of comedonecrosis in tumor. (D) Isolated
transition zone cancer visible as an amorphous hypoechoic bulge of the right anterior transition zone (arrows). DRE was negative. Biopsy to
investigate PSA of 12.0 ng/mL showed Gleason 6/10 cancer. (E) Typical hypoechoic peripheral zone lesion. Biopsy showed Gleason 8/10 cancer
(arrow). (F) Power Doppler scan shows enhanced vascularity in lesion (arrow). (G) Elastography of same lesion (arrow) in (F) shows blue color
in lesion, implying stiff tissue. (H) T2-weighted magnetic resonance imaging (T2W MRI) scan shows suspicious “charcoal” texture lesion bulging
capsule in the right anterior ibromuscular zone (arrow). Prior systematic biopsy indings were not unexpectedly negative because only the posterior
2 cm of the prostate would be sampled. (I) Corresponding TRUS shows the same lesion. Such lesions are often missed on TRUS because attention
and biopsy are conined to the posterior peripheral zone and because the procedure is performed by operators who use TRUS only to guide systematic
biopsy without irst evaluating the gland.
with the surrounding prostate gland (see Figs. 10.16C and 10.17A).
When present, an isoechoic tumor can be detected only if secondary
signs are appreciated, including glandular asymmetry, capsular
bulging, and areas of attenuation. his is oten true of transition
zone cancer 127,130 (see Figs. 10.16E and 10.17D, H, and I).
When the tumor replaces the entire peripheral zone, it oten
is less echogenic than the inner gland, which is a reversal of the
normal sonographic relation. When the entire gland is replaced
with tumor on a BPH background, the gland may be difusely
inhomogeneous (see Fig. 10.17B).
Only about half of hypoechoic areas are cancer. 131 Other
benign causes of hypoechoic areas seen in the prostate include
normal internal sphincter muscle, hyperplasia, prostatitis,
hematoma, vessels, benign glandular ectasia, and cysts. 2,91,127
Fortunately, 70% of prostate cancers arise in the homogeneous
peripheral zone where the homogeneous background makes