Small Animal Radiology and Ultrasound: A Diagnostic Atlas and Text

Chapter Three The Abd omen 447
Fig. 3-262 A 5-year-old male
Beagle with a retained testicle, ventral
alopecia, and enlarged nipples.
There is a tissue-dense mass in the
caudal abdomen (black arrow) and
enlarged sublumbar lymph nodes
(white arrow). Differential diagnoses
include testicular tumor (Sertoli cell
tumor, seminoma), nonobstructing
small intestinal mass (leiomyosarcoma),
or tumor or granuloma arising
from the mesentery. Diagnosis:
Sertoli cell tumor with metastasis to
the sublumbar lymph nodes.
Fig. 3-263 Longitudinal (A) and
transverse (B) sonograms of the left
testicle of an 8-year-old male
Labrador Retriever with a history of
fecal incontinence, hematuria, and
pyrexia. There is a well-defined
hypoechoic lesion in the caudal portion
of the testes. This is indicative of
a testicular tumor. Diagnosis: Sertoli
cell tumor.
A
B
depending on the circumstances. They can be recognized, when found, because of their
normal hyperechoic appearance despite their abnormal location. 887 The testicle may
appear hypoechoic when it is atrophied.
Doppler examination has been used in humans to distinguish testicular torsion from
testicular neoplasia. Because testicular torsion is rare and most neoplasms are small, this
may not be necessary in dogs. Orchitis and torsion may produce fluid within the scrotum.
Ultrasonography can be used to identify and evaluate the testicle within the fluid-distended
scrotum when it cannot be palpated. Ultrasonography can distinguish the testicular from
the nontesticular causes for scrotal swelling and can differentiate unilateral from bilateral
disease (Fig. 3-265). 887,888
A diffuse, patchy hypoechoic pattern has been identified with orchitis in dogs.
Enlargement of the epididymis also has been observed. 887