5.5-year-old neutered male Schnauzer
Recent onset of stranguria, history of calcium oxalate urolithiasis
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A 5.5 year old male altered Schnauzer presented with a recent onset of stranguria. Past medical history included a cystotomy for removal of calcium oxalate calculi and conservatively treated pelvic fractures associated with vehicular trauma. An abdominal ultrasound, performed by the referring DVM, reported a cystic mass near the bladder or dilated ureter and a possible cyst in the prostate.
CT excretory urogram was performed. Pre-contrast study and 5 minute and 20 minute post contrast administration images are provided.
Abdominal CT, soft tissue window
Abdominal CT, 5 min +C
Abdominal CT, 20 minutes +C
In the left inguinal soft tissues there is a tubular structure, measuring 9 mm in diameter, which courses through the left inguinal canal to enter the left abdomen, and continues dorsal to the urinary bladder. At the level of the bladder the structure crosses the midline, continues cranially and terminates at a right lateral mixed attenuating abdominal mass. The right lateral abdominal mass, measuring 4.0 cm x 4.2 cm x 3.4 cm (craniocaudal x mediolateral x dorsoventral), is caudal to the right kidney, craniolateral to the urinary bladder and is heterogeneously contrast enhancing. An additional tubular mass, measuring 1.4 cm in diameter, is present dorsal to the urinary bladder and ventral to the colon, and appears unassociated with the bladder wall or prostate. No visible cysts are identified in the prostate. A small right renal calculus, urinary bladder calculi, a cholelith, and a healed pubic fracture are present.
The right and left ureters are normal.
Summary
1. Retained abdominal testis and testicular neoplasm.
2. Cystic mass dorsal to the urinary bladder.
Differentials are ductus deferens enlargement or ductus deferens neoplasm or uterus masculinus.
3. Normal prostate
4. Small right renal calculus, urinary bladder calculi, cholelith and healed pubic fracture.
Final Microscopic Diagnosis:
1. Cryptorchid testis and Sertoli cell tumor with necrosis and hemorrhage.
2. Uterus masculinus.
3. Prostatic atrophy and fibrosis with few cysts. No prostatitis or neoplasia.
Comments:
The presence of a uterus masculinus makes the patient a male pseudohermaphrodite and exhibits features of persistent mullerian duct syndrome (PMDS). PMDS is often associated with cryptorchidism, although the cause of this association is undetermined in dogs. Neoplastic transformation of retained testes is well described; therefore, PMDS is also associated with testicular neoplasia. PMDS is a hereditary disorder in Schnauzers and Basset hounds. In miniature schnauzers PMDS is attributed to a sex-limited autosomal recessive trait. Approximately half of these dogs will show a feminization syndrome. Neither the owner nor the DVM noted any such traits in this dog. Serum estrogen levels were not performed.
Reference:
Vegter AR, Kooistra HS, et al. Persistent Mullerian Duct Syndrome in a Minature Schnauzer Dog with Signs of Feminization and a Sertoli Cell Tumor. Reprod Dom Anim 2010; 45:447-452.