Diagnostic ultrasound ( PDFDrive )

CHAPTER 22 The Scrotum 841
dilated vas deferens may be seen in addition to the enlarged
epididymis. An unusual appearance described as “dancing
megasperm” is occasionally seen in patients with vasectomy
(Video 22.5). High relective echoes within the dilated epididymis
appear to move independently, shown histologically to be aggregations
of spermatozoa and macrophages. 152
FIG. 22.24 Polyorchidism. Transverse extended ield of view image
of the right hemiscrotum shows a right testis (R) and two additional
intrascrotal masses with similar imaging characteristics to the right testis
(*) consistent with supernumery testes in an asymptomatic patient with
a palpable mass.
eferent ductules of the epididymal head. hey generally present
as a hard, palpable mass, and at ultrasound appear as an echogenic,
solid mass with distinct, small cystic spaces.
he majority of solid epididymal masses are benign. However,
primary extratesticular scrotal malignant neoplasms do
occur, including adenocarcinoma, ibrosarcoma, liposarcoma
(see Fig. 22.23E and F), histiocytoma, and lymphoma in adults
and rhabdomyosarcoma in children (see Fig. 22.23H). Metastatic
tumors to the epididymis are also rare. he most common primary
sites include the testis, stomach, kidney, prostate, colon, and,
less oten, the pancreas 146,147 (see Fig. 22.23I). Size of the lesion
and the presence of color low may be helpful in the diagnosis
of extratesticular scrotal masses. 23,148 Larger masses (>1.5 cm)
with prominent color low that present without cl inical symptoms
of inlammation are more likely to be malignant. 23,148
Sperm Granuloma
Sperm granulomas are thought to arise from extravasation of
spermatozoa into the sot tissues surrounding the epididymis,
producing a necrotizing granulomatous response. 3 hese lesions
may be painful or asymptomatic, and they are most oten found
in patients ater vasectomy. It is assumed that vasectomy produces
increased pressure in the epididymal ductules, causing rupture
with subsequent formation of sperm granulomas. Sperm granulomas
may also be associated with prior epididymal infection
or trauma. he typical sonographic appearance is that of a solid,
hypoechoic or heterogeneous mass, usually located in or adjacent
to the epididymis, although it may simulate an intratesticular
lesion (Fig. 22.26A). Chronic sperm granulomas may contain
calciication. 149
Postvasectomy Changes in the Epididymis
Sonographic changes in the epididymis are very common in
patients ater vasectomy. 150,151 In addition to the formation of
sperm granulomas, these indings include epididymal enlargement
with ductular ectasia involving the epididymis (Fig. 22.26B) and
rete testis, as well as the development of cysts (Video 22.4). A
Chronic Epididymitis
Chronic epididymitis is more commonly seen with conditions
associated with granulomatous reactions, including tuberculosis,
brucellosis, syphilis, and parasitic and fungal infections. 60
Tuberculosis epididymal infections are the most common of
these and are believed to result from renal disease seeding the
lower genitourinary tract, with 25% of patients having bilateral
involvement. 153 Patients with chronic granulomatous epididymitis
caused by spread of tuberculosis from the genitourinary tract
complain of a hard, nontender scrotal mass. 14 Sonography most
oten shows a thickened tunica albuginea and a thickened,
irregular epididymis with variable appearance (Fig. 22.27).
Calciication may be identiied within the tunica albuginea or
epididymis. 3 Associated indings include hydroceles, scrotal wall
thickening, and istulas. 153 Untreated granulomatous epididymitis
can spread to the testes, causing an epididymo-orchitis, although
this is less common than isolated epididymal disease. Focal
testicular involvement may demonstrate a variable sonographic
appearance and may simulate the appearance of a testicular
neoplasm on sonography. Patients may also develop chronic
epididymitis ater episodes of acute bacterial epididymitis that
do not subside.
Sarcoidosis
Sarcoidosis is a noninfectious, chronic, granulomatous disease
that may involve the genital tract. 154-156 In an autopsy series,
approximately 5% of cases had genital tract involvement, with
the epididymis most frequently involved. 60 he clinical presentation
is acute or recurrent epididymitis or painless enlargement
of the testis or epididymis. Sonographically, sarcoid lesions are
irregular, hypoechoic solid masses in the testis or epididymis
(Fig. 22.28). Occasionally, hyperechoic, calciic foci with acoustic
shadowing may be seen. Distinguishing sarcoidosis from an
inlammatory process or a neoplasm is diicult on sonography
alone. Resection or orchiectomy may be necessary for deinitive
diagnosis. As noted previously, tuberculosis can also cause a
chronic granulomatous reaction of the genital tract, typically a
granulomatous epididymitis.
ACUTE SCROTAL PAIN
Acute scrotal pain may have numerous causes. More common
causes include torsion of the spermatic cord and testis,
epididymitis or orchitis, torsion of a testicular appendage,
acute hydrocele, strangulated hernia, idiopathic scrotal
edema, Henoch-Schönlein purpura, abscess, traumatic
hemorrhage, hemorrhage into a testicular neoplasm, and
scrotal fat necrosis. Torsion of the spermatic cord and acute
epididymitis or epididymo-orchitis are the most common causes
of acute scrotal pain. hese entities cannot be distinguished by