Introduction

• Cause: paraprostatic cysts (PPC), etiology unknown, prostatic retention cysts (PRC), concurrent prostatic disease.
• Vary in size (milliliters to liters).
• Signs: defecatory tenesmus, dysuria, incontinence, abdominal mass/distension, urethral blood.
• Diagnosis: radiography and ultrasound +/- biopsy.
• Treatment: resection, omentalization.
• Prognosis: good unless associated with neoplasia.

Pathogenesis

Etiology

• Paraprostatic cysts - unknown (?congenital) only fascial attachment to prostate.
• Prostatic retention cysts - concurrent prostatic disease, wide based intimacy of bladder neck to prostate.

Predisposing factors

• Older, intact males, large breed dogs.

Specific

• Sertoli cell tumors (endogenous estrogen) or exogenous estrogens can result in squamous metaplasia and obstruction of gland.
• Obstruction of glands results in accumulation of prostatic secretions and formation of cysts.
• Cysts coalesce and can become confluent to form larger cavities.
• As cyst enlarges, compression of surrounding organs (colon, bladder) can result in clinical signs.
• Cysts can become infected and abscessate.

Pathophysiology

• Paraprostatic cysts: unknown - may be congenital in origin (remnant of uterus masculinus). No communication with prostate, urethra or bladder.
• Prostatic retention cysts: obstruction of ducts within parenchyma of gland results in accumulation of prostatic secretions. Usually occurs with concurrent disease (benign prostatic hyperplasia, abscess, neoplasia, squamous metaplasia).

Timecourse

• Months.

Diagnosis

Treatment

Prevention

Outcomes