Diagnostic ultrasound ( PDFDrive )

832 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
be helpful; however, orchiectomy is frequently necessary to obtain
a histologic diagnosis. 96,97
Segmental Infarction
Segmental testicular infarction may occur ater torsion, trauma,
surgery, bacterial endocarditis, vasculitis, leukemia, or hypercoagulable
states. 98 Spontaneous infarction of the testis is rare.
he sonographic appearance depends on the age of the infarction.
Initially, a typical segmental infarct is seen as a focal, wedgeshaped
or round hypoechoic mass, with approximately 80%
occurring in the upper pole, likely secondary to vascular supply
between the upper and lower poles. 99 he focal hypoechoic mass
may not be distinguishable from a neoplasm on the basis of its
gray-scale sonographic appearance. 100,101 hese lesions should
have reduced or absent blood low, depending on the age of the
infarction. 99 If a well-circumscribed, nonpalpable, relatively
peripheral, hypoechoic mass shows a complete lack of vascularity
on power Doppler imaging or ater the administration of sonographic
contrast agent, it may be possible to distinguish such
benign infarctions from neoplasm 102,103 (Fig. 22.14). With time,
the hypoechoic mass or the entire testis oten decreases in size
and develops areas of increased echogenicity because of ibrosis
or dystrophic calciication. 104 he early sonographic appearance
may be diicult to distinguish from a testicular neoplasm, but
infarcts decrease substantially in size, whereas tumors characteristically
enlarge with time. 3,101,105
Adrenal Rests
Adrenal rests are a rare cause of intertesticular masses and can
be seen in the setting of congenital adrenal hyperplasia (CAH),
and rarely in the setting of Cushing syndrome. CAH is an
autosomal recessive disease involving an adrenocortical enzyme
defect. his disease typically becomes clinically obvious early in
life or in early adulthood. Patients oten present with a testicular
mass or enlargement, precocious puberty, and with or without
salt-depletion syndrome. Adrenal rests arise from aberrant
adrenocortical cells that migrate with gonadal tissues in the fetus.
hey can form tumorlike masses in response to elevated levels
A
B
C
D
FIG. 22.14 Testicular Infarcts: Spectrum of Appearances. (A) and (B) Acute infarct. (A) Longitudinal power Doppler scan shows an avascular
area at the upper pole from partial torsion. (B) Longitudinal color Doppler scan shows an avascular area in the midtestis caused by vasculitis.
(C) and (D) Chronic infarct. (C) Longitudinal scan shows a peripheral wedge-shaped hypoechoic area caused by prior mumps orchitis. (D)
Longitudinal power Doppler scan shows lack of vascularity in the lower pole.