Diagnostic ultrasound ( PDFDrive )

CHAPTER 22 The Scrotum 829
located within the parenchyma. Cystic testicular lesions are not
always benign; testicular tumors (especially NSGCTs) can undergo
cystic degeneration from hemorrhage or necrosis. he distinction
between a benign cyst and a cystic neoplasm is of utmost clinical
importance (Fig. 22.12). Simple intratesticular cysts can be
managed conservatively without the need for surgical intervention.
73 Of the 34 cystic testicular masses discovered with
sonography by Hamm et al., 72 16 were neoplastic, and all of these
had sonographic features of complicated cysts. NCGCTs, especially
those with teratoma elements, are the most common tumors to
contain both cystic and solid components.
FIG. 22.11 Multiple Testicular Hamartomas in Cowden Disease.
Dual transverse image shows multiple bilateral small echogenic hamartomas.
The patient had Cowden disease, an inherited autosomal
dominant disorder, which causes multiple hamartomas in the gastrointestinal
tract.
on sonographic examination with marked hypervascularity. 67,68
Bilateral involvement occurs in approximately 20% of cases. 47
Metastatic Disease
Nonlymphomatous metastases to the testes are uncommon,
representing 0.02% to 5% of all testicular neoplasms. 69 he most
frequent primary sites are the lung and prostate gland. 42 Other
frequent primary sites for metastatic neoplasms include melanoma,
kidney, colon, stomach, and pancreas. 70 Most metastases are
clinically silent, being discovered incidentally at autopsy. Testicular
metastases are most common in patients during the sixth and
seventh decades. 3 hey are usually multiple and are bilateral in
15% of cases. 42 Because primary germ cell tumors may also be
multicentric and bilateral, these features are not helpful in distinguishing
primary from metastatic testicular neoplasms.
Widespread systemic metastases are usually present in patients
with testicular metastases. Possible routes of metastases to the
testis include retrograde venous, hematogenous, retrograde
lymphatic, and direct tumor invasion. Metastases from sites remote
from the testis, such as the lung and skin, most likely spread
hematogenously. Retrograde venous extension through the testicular
vein occurs in renal cell carcinoma and may also occur in
urinary bladder and prostate tumors. 71 Neoplasms with metastases
to the periaortic lymph nodes may involve the testis through
retrograde lymphatic extension. Sonographic features of nonlymphomatous
testicular metastases vary. he appearance is oten
hypoechoic but may be echogenic or complex 3 (Fig. 22.10F).
Other rare tumors of the testis include hamartoma (Fig. 22.11),
dermoid tumor, hemangioma, intratesticular adenomatoid tumor,
carcinoid tumor, carcinoma of the mediastinum testis, neuroectodermal
tumor, leiomyoma, Brenner tumor, ibroma, ibrosarcoma,
osteosarcoma, chondrosarcoma, and undiferentiated
sarcoma, among others.
Benign Intratesticular Lesions
Cysts
Intratesticular cystic lesions are discovered incidentally on
sonography in 8% to 10% of men. 72 Benign testicular cysts may
be associated with the tunica albuginea, tunica vaginalis, or
Testicular Cystic Lesions
BENIGN
Tunica albuginea cysts
Tunica vaginalis cysts
Intratesticular cysts
Tubular ectasia of rete testis
Cystic dysplasia
Epidermoid cysts
Abscess
MALIGNANT
Nonseminomatous germ cell tumor
Necrosis or hemorrhage in tumor
Tubular obstruction by tumor
Cysts of the tunica albuginea are located within the tunica,
which surrounds the testis. hey vary in size from 2 to 30 mm
and are well deined. hey are usually solitary and unilocular
but may be multiple or multilocular 72,74 (Fig. 22.12A). he mean
age at presentation is 40 years, but cysts also occur in the ith
and sixth decades. 75 he cysts may be asymptomatic, but patients
frequently present with cysts that are clinically palpable, irm
scrotal nodules. Histologically, they are simple cysts lined with
cuboid or low columnar cells and illed with serous luid. 76 Careful
scanning in multiple planes allows delineation of the cyst as
arising from the tunica albuginea and clariies its benign nature.
Complex tunica albuginea cysts may simulate a testicular
neoplasm. 77
Cysts of the tunica vaginalis are rare and arise from the
visceral or parietal layer of the tunica vaginalis. hey may be
single or multiple. Sonographically, they usually appear anechoic
but may have septations or may contain echoes caused by
hemorrhage. 78
Intratesticular cysts are simple cysts illed with clear serous
luid; they vary in size from 2 to 18 mm. 79 Sonographically, they
are well-deined, anechoic cysts with thin, smooth walls and
posterior acoustic enhancement. Hamm et al. 72 reported that in
all 13 of their cases, the cysts were located near the mediastinum
testis, supporting the theory that they originate from the rete
testis, possibly secondary to posttraumatic or postinlammatory
stricture formation (Fig. 22.12B).
Tubular Ectasia of Rete Testis
Tubular ectasia of the rete testis is a benign, normal variant that
may be mistaken for a testicular neoplasm. 80-83 Dilatation of the