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Testicular Tumors 963

Differential Diagnosis
• Testicular torsion
VetBooks.ir • Cyst Diseases and Disorders
• Abscess
Initial Database
• CBC: rule out bone marrow suppres-
sion due to Sertoli cell tumor–associated
hyperestrogenism.
• Semen evaluation and/or testicular biopsy
with histologic exam of unaffected testis
can aid in decision for unilateral or bilateral
castration in breeding dogs. A B
Advanced or Confirmatory Testing TESTICULAR TUMORS A, Transscrotal ultrasonogram of left testis of a normal fertile male dog. Echotexture
• Ultrasound, all tumor types: hypoechoic or of the parenchyma is homogeneous, with the exception of the hyperechoic mediastinum (rete testis; arrow). B,
mixed echotexture Transscrotal ultrasonogram of left testis of an infertile male dog. Two anechoic cystic structures are seen within
• Cytologic evaluation of abnormal testis the parenchyma on either side of the mediastinum. Differential diagnoses include cystic neoplasia or testicular
cyst. (Courtesy Dr. Michelle A. Kutzler.)
• Gross pathologic exam of excised testis
○ Seminoma signs include soft to slightly
firm testis; homogeneous, gray/white,
glistening appearance; possible areas Methotrexate, vincristine, and cyclophos- PEARLS & CONSIDERATIONS
of discoloration due to hemorrhage or phamide; cisplatin; bleomycin; and radiation
necrosis; focal to multifocal therapy have been reported to have some degree Comments
○ Sertoli cell tumor signs include very firm of efficacy. • Histopathologic exam is needed for deter-
testis that are discrete, white or gray, with mination of tumor type.
possible tan or yellow hemorrhagic areas; Behavior/Exercise • Unilateral castration may result in up to
usually focal Avoid estrous females, and restrict physical 50% compensatory hypertrophy of the
○ Leydig cell tumor signs include soft testis activity for approximately 1 week after surgery. remaining testis. Return to fertility after
that are discrete and yellow/brown, bulges unilateral castration depends on the severity
on section, areas of hemorrhage or cystic Possible Complications of testicular atrophy secondary to hormonal
change common, focal to multifocal • Bone marrow suppression (hyperestrogenism) downregulation and presence of underlying
○ Mixed germ cell/stromal tumor signs from Sertoli cell tumors disease (testicular degeneration with loss of
include various textures and pale white • Behavioral changes (hyperandrogenism) from spermatogonia).
or gray appearance; generally discrete and Leydig cell tumors
focal Prevention
• Bilateral tumors are common, and multiple Recommended Monitoring Testicular removal, especially of cryptorchid
tumor types often occur in the same testis. • Seminoma, Leydig cell tumor, nonactive testes
• Histopathologic exam: include spermatic cord Sertoli cell tumor, mixed sex cord–stromal
to evaluate for local invasion; multiple tumor tumor: yearly physical exam Technician Tips
types can occur in the same testis. • Sertoli cell tumor with bone marrow suppres- • Make a longitudinal incision into testes
sion: close follow-up resolution of anemia, greater than 2.5 cm in diameter to aid in
TREATMENT thrombocytopenia, and leukopenia; yearly fixation for histopathology submission.
physical exam after marrow recovery • When fixing, use an adequate amount of
Treatment Overview formalin (1 part tissue to 9 parts formalin).
Therapy consists of surgical removal of the PROGNOSIS & OUTCOME
affected testis. Client Education
• Seminoma: excellent after testicular removal; • Regular exam of testes and evaluation of the
Acute General Treatment metastasis is rare. semen in breeding animals
• Testicular removal: castration; unilateral • Sertoli cell tumor: excellent after testicular • Prompt presentation for veterinary exam if
castration if contralateral testis is normal removal; metastasis is rare, but risk of an abnormality is detected
to small and future breeding with the dog metastasis is increased for tumors > 2 cm
is desired diameter. SUGGESTED READING
• Supportive care for dogs with Sertoli cell • Leydig cell tumor: excellent after testicular Agnew DW, et al: Tumors of the genital systems. In
tumor–associated bone marrow suppression removal; metastasis is not expected. Meuten DJ, editor: Tumors in domestic animals, ed
• Mixed sex cord–stromal tumor: excellent 5, Ames, IA, 2017, Wiley Blackwell, pp 706-714.
Chronic Treatment after testicular removal; metastasis is not
For metastatic seminoma, both chemotherapy expected. AUTHOR: Beth A. Valentine, DVM, PhD, DACVP
EDITOR: Michelle A. Kutzler, DVM, PhD, DACT
and radiation therapy have been described.

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