Radiographic diagnosis: mineralized paraprostatic cyst in a dog

Abstract

A 32-kg, 4-year-old, male neutered golden retriever. HistoryThe dog was examined at the Veterinary Medical Teaching Hospital at the University of Wisconsin because of 2month history of intermittent hematuria and bloody penile discharge. The dog had been neutered 1 month prior to clinical signs and 3 months prior to referral to the Veterinary Medical Teaching Hospital. One month prior to presentation, the referring veterinarian identified a large firm bladder on abdominal palpation and noted difficulty in advancing a needle for cystocentesis. The aspirated fluid was bloody, different from the clear urine observed during urination. The dog was treated with enrofloxacinin à (68 mg PO BID), with no improvement in clinical signs. Physical FindingsThere was a large firm mass in the caudal abdomen. The remainder of the examination was unremarkable. Radiographic FindingsA teardrop-to oval-shaped mass with a mineralized wall was present in the caudal abdomen ( Figs. 1A and 1B). A small, mineralized stalk was also noted extending from the mass caudally to the pelvic inlet. A second oval-to teardrop-shaped structure was noted dorsal and to the left of the mineralized mass, and thought to represent the urinary bladder. The radiographic diagnosis was mineralized paraprostatic cyst. Other differential diagnoses included an atypical mineralized granuloma, neoplasia, abscess, mesenteric cyst, or mineralized urinary bladder. 1,2 Ultrasonographic FindingsAn 11  7.9  8.1 cm ovoid mass with a hyperechoic nonshadowing wall and hypoechoic contents with a small amount of dependent echogenic luminal material was seen (Fig. 2). The urinary bladder was identified as a separate Fig. 1. Right lateral (A) and ventrodorsal (B) radiographs of caudal abdomen.There is a teardrop-shaped structure with a thin mineralized wall representing the paraprostatic cyst (white arrows) noted ventrally and to the right of midline. A second soft-tissue ovoid structure is present dorsal and to the left of cyst, and represents urinary bladder (black arrows).

Two Cases of Paraprostatic Cysts in Castrated Male Dogs

“…In those cases, while the dogs were castrated at the time of diagnosis of the paraprostatic cysts, castration had been performed only one and three months prior to referral, respectively. 3,8 It seems unlikely that the cysts would have developed in such a short amount of time and grown large enough to cause the clinical signs that were described in those reports. It is possible that the paraprostatic cysts were testosterone-dependent and therefore developed while the dogs were intact, and not after castration.…”

“…Survey abdominal radiography with or without contrast cystography will often reveal a round structure of softtissue or mineralized opacity dorsal to, and possibly displacing, the urinary bladder. 3,4,7,8,10,11 Abdominal ultrasonography can also be used to assess the prostate gland and any abnormal abdominal structures. Two studies have evaluated the ultrasonographic features of paraprostatic cysts.…”

Unusual presentation of alveolar echinococcosis as prostatic and paraprostatic cysts in a dog

“…Cystic enlargements in older dogs are reported to be stimulated by hyperoestrogenism associated with Sertoli cell tumors [34]. Although only 2 cases of paraprostatic cysts have been described in neutered male dogs [32], they should be considered a differential diagnosis in castrated male dogs with large prostatic cystic lesions [31,32,34,35]. Moreover, normal paraprostatic cysts may also be mineralized or even show bone formation.…”

What Is Your Diagnosis?

“…1,3 Abdominal radiography is also helpful in the diagnosis of paraprostatic cysts; mineralized paraprostatic cysts are fairly characteristic on a standard radiographic view of the abdomen. 2,4 In this dog, ultrasonography revealed the presence of a prostate with a heterogeneous appearance and paraprostatic cysts. Findings on cytologic evaluation of the prostate were consistent with benign prostatic hypertrophy.…”