**Sertoli Cell Tumor in a Previously Neutered Dog**

Sonographer: Kara Woody DVM

Patient Information:

Age: 7 years

Gender: Neutered Male

Breed: Beagle

Species: Canine

History

Mass in scrotum with feminization and suspected prostatitis

Laboratory Findings

Hematuria, pyuria

Ultrasonographic Findings

The prostate is severely enlarged (HXLXW=2.7x5.3x4.2cm) with a severely heterogenous mixed echogenic echotexture with multi-focal cavitations present throughout the parenchyma.
There is a rounded severely heterogenous mixed echogenic mass (1.4x2.2cm) present in the scrotum.

Abdominal Ultrasound Interpretation

Testicular Tumor - the findings are moderate - DDx: sertoli cell tumor, seminoma, interstitial cell tumor vs. benign orchitis or testicular torsion.
Prostate - the findings are moderate-severe - DDx: squamous metaplasia vs benign prostatic hyperplasia vs. prostatitis (bacterial vs. sterile) vs. prostatic neoplasia (transitional cell carcinoma arising from the urethra and prostatic duct epithelium vs. adenocarcinoma).

Cytology Results

Ultrasound guided fine needle aspirates were performed of the prostate and scrotal mass and submitted for cytological interpretation. Results were consistent with Sertoli Cell tumor for the scrotal mass and squamous cell metaplasia with marked neutrophilic inflammation for the prostate. Sertoli Cell tumor was confirmed with histopathology after removal.

Comments

Squamous metaplasia is a common sequela of increased estrogen levels (from the Sertoli Cell tumor in this case). This is a highly inflammatory condition and the cause of the significant prostatitis in this patient. With removal of the estrogen source, full resolution of the prostatitis is expected. What is particularly puzzling about this case is the development of a testicular tumor in a previously neutered patient. Several explanations have been proposed in the literature. The most plausible explanation is the seeding of testicular cells from excessive pressure to the testis or inadvertent incision of the tunica albuginea during castration. Less likely explanations include polyorchidism or the presence of embryological testicular remnants. (Can Vet J. 2006 Aug; 47(8): 763-766.)