Diagnostic Ultrasound - Abdomen and Pelvis

Adenomatoid Tumor
Diagnoses: Scrotum
TERMINOLOGY
• Benign solid paratesticular tumor of mesenchymal origin
IMAGING
• Solid intrascrotal mass, usually extratesticular
• Location
○ Epididymis: Most common location overall
○ May arise in tunica albuginea
○ Rarely intratesticular or other locations such as spermatic
cord and prostate
• Imaging appearance
○ Rounded or ovoid
○ Well circumscribed
○ Varying echogenicity
○ Gentle transducer pressure may show mass can move
independently of testis
○ Refractive edge shadows on grayscale US
○ Hypovascular or avascular on color Doppler US
○ Size: 5 mm to 5 cm
KEY FACTS
TOP DIFFERENTIAL DIAGNOSES
• Leiomyoma
• Lipoma
• Cystadenoma
CLINICAL ISSUES
• Most common solid mass in epididymis
○ 36% of all paratesticular tumors
• Slowly enlarges over years
• Most surgically excised to confirm diagnosis
• Some urologists and patients elect surveillance
• Age: 20 years and older
○ Mean age 36
○ Rarely seen in boys
DIAGNOSTIC CHECKLIST
• Consider leiomyoma
(Left) This palpable
hypoechoic adenomatoid
tumor located in the in tail
of the epididymis in a 41-yearold
man has no demonstrable
internal vascularity. (Right)
This 50-year-old man had 5
years of ultrasound
surveillance for a presumed
adenomatoid tumor. This
ovoid, well-circumscribed mass
in the tail of the epididymis
is isoechoic to testis and shows
minimal internal vascularity
. Note the very different
echogenicity compared to the
otherwise similar patient
shown previously.
(Left) This hyperechoic ovoid
adenomatoid tumor in the
tail of the epididymis was an
incidental finding in a 37-yearold
man. (Right) This
adenomatoid tumor of the
tunica albuginea was
incidentally noted on a pelvic
MR in a 12-year-old boy. The
lesion is equally endophytic
and exophytic to the testis as
it is centered in the tunica.
Note minimal internal
vascularity.
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