Diagnostic ultrasound ( PDFDrive )

830 PART III Small Parts, Carotid Artery, and Peripheral Vessel Sonography
A
B
C
D
E
F
G
H
FIG. 22.12 Intratesticular Cystic Lesions. (A) Tunica albuginea cyst. Longitudinal scan shows a cyst arising from the tunica albuginea. These
cysts are usually palpable. (B) Intratesticular cyst. Transverse scan shows bilateral benign intratesticular cysts. (C) Cystic dilatation in rete testis.
Transverse scan shows dilated tubules of the rete testis in both testes. (D)-(F) Epidermoid cyst (benign). See also Video 12.2. (D) Typical whorled
appearance; (E) heterogeneous hypoechoic lesion (arrows); (F) typical peripheral calciications. (G) Transverse scan shows an intratesticular cystic
lesion with minimal mural nodularity (arrow). (H) Transverse scan at 6-month interval follow-up shows interval development of an isoechoic, solid
mass (arrow) partially illing the cystic lesion, surgically proven to represent teratoma. (G and H courtesy of Shane Macauley, MD.)
rete testis is thought to result from obstruction in the eferent
tubules or epididymis, with epididymal obstruction caused by
inlammation, trauma, or surgery. Sonographic appearance is of
multiple luid-illed tubular structures in or adjacent to the
mediastinum testis with no associated sot tissue abnormality
and no low on color low Doppler imaging (Fig. 22.12C). Rete
testis dilatation is oten bilateral, asymmetric, and is frequently
associated with a spermatocele. he characteristic sonographic
appearance and location should allow recognition as a benign
condition, thus preventing an orchiectomy. Characteristic indings
of the dilated rete testis on magnetic resonance imaging (MRI)
include intratesticular signal intensity similar to that of luid in
the region of the mediastinum testis. 80 his appearance is in
contrast to the MRI appearance of testicular tumors, which
typically have low signal intensity on T2-weighted imaging.
Cystic Dysplasia
Cystic dysplasia is a rare congenital malformation, usually
occurring in infants and young children, although one case
was reported in a 30-year-old man. 84,85 his lesion is thought
to result from an embryologic defect that prevents connection
of the tubules of the rete testis and the eferent ductules.
Pathologically, the lesion consists of multiple, interconnecting
cysts of various sizes and shapes, separated by ibrous septa. his
lesion originates in the rete testis and extends into the adjacent
parenchyma, resulting in pressure atrophy of the adjacent
testicular parenchyma. he cysts are lined by a single layer of
lat or cuboidal epithelium. Sonographically, the appearance
is similar to acquired cystic dilatation of the rete testis. Renal
agenesis or dysplasia frequently coexists with testicular cystic
dysplasia. 85