November's Case of the Month
Interstitial Cell Testicular Tumor in an Intact Male
Dr. Kara Woody
Patient Information:
Age: 9 years
Gender: Male
Breed: Chihuahua
Species: Canine
History:
Prostatomegaly was identified on abdominal radiographs. No reported urinary signs.
Laboratory Findings:
Mild elevation in BUN. Normal creatinine and SDMA. Urinalysis was obtained later and results were not available at time of scan.
Ultrasonographic Findings:
Testicles: The left testicle was mildly enlarged when compared to the right (Lt/Rt-1.2x2.4cm/1.1x1.9cm). There was an ill-defined homogenous mildly hypoechoic nodule (0.5x0.7cm) present in the left testicle. There were no focal lesions in the right testicle.
Prostate: Moderate enlargement (HxWxL=2.8x3.7x4.4cm) with hyperechoic coarse echogenicity and multifocal small cysts (~0.5cm diameter) throughout.
Abdominal Ultrasound Interpretation: Left Testicular tumor-the findings were mild-DDX: interstitial cell tumor vs seminoma vs sertoli cell tumor (most likely in free abdominal cryptorchid testciles) vs benign orchitis
Prostate - the findings were moderate - DDx: benign prostatic hyperplasia vs. prostatitis (bacterial vs. sterile) vs. prostatic neoplasia (less likely)
Discussion:
Interstitial cell tumors are common testicular tumors in dogs. Castration is typically curative as it provides complete excision and metastasis is rare. The changes in this patient’s prostate were likely not worsened by this mass since androgen/estrogen production is rare.
Benign prostatic hyperplasia is common in older intact male dogs due to androgen effects upon the gland. The prostate is typically symmetrically enlarged and non-painful. Some dogs show no clinical signs like this patient, but others may display hematuria and tenesmus. Castration is typically curative with complete resolution of clinical signs within a few weeks.
This case highlights the importance of complete ultrasonographic evaluation of the testicles during abdominal ultrasound exams in intact males.
Image 1: Prostatomegaly with a coarse hyperechoic echogenicity and multiple small anechoic cysts. This is a typical appearance of benign prostatic hyperplasia.
Image 2: A subtle ill-defined mildly hypoechoic nodule is noted in the left testicle.
Image 3: Gross appearance of an interstitial cell tumor in a canine. Photo credit: vet.cornell.edu
Special thanks to Banfield Mechanicsville for allowing us to collaborate on this case.