Wednesday, March 7, 2018

Cowpers duct syringocele

Ryan Schwope

Ryan Schwope

Ryan Schwope
Axial contrast-enhanced CT (top), axial T2W MRI (middle), and sag T2W with fat-saturation MRI (bottom)
demonstrate an ovoid cystic structure associated with the midline posterior aspect of the bulbous urethra
  • The Cowper glands (bulbourethral glands) are paired pea-sized accessory exocrine glands analogous to the Bartholin glands in females
    • The main glands lie within the urogenital diaphragm
    • The ducts insert into the bulbous urethra  
    • Provide lubrication of the urethra and protection of the sperm
  • Obstruction of the ducts may result in formation of retention cysts, also referred to as syringoceles
    • May be congenital or acquired 
    • Most often asymptomatic although when large, may result in urinary obstruction and hematuria
  • Categorized as either open or closed 
    • Open cysts communicate with the lumen of the urethra and may mimic a urethral diverticulum or even an ectopic ureter
      • More likely to cause symptoms of postvoid dribbling, purulent discharge and hematuria
    • Closed or imperforate cysts become dilated due to duct obstruction resulting in cyst dilatation and extrinsic mass effect on the bulbar urethra
      • More likely to result in obstructive symptoms
  • Imaging typically detects a Cowper duct cyst as a unilocular cystic lesion at the posterior or posterolateral aspect of the posterior urethra 
    • Open cysts may be opacified during urethrography 
    • Closed cysts may appear as a smooth extrinsic filling defect on the ventral wall of the bulbous urethra 
    • MRI is useful to exclude solid neoplasms and to detect complications such as hemorrhage or infection
  • Symptomatic cases are treated surgically with cyst unroofing. Transperineal ligation of the Cowper gland ducts may be performed in refractory cases


Thursday, March 1, 2018

Persistent Sciatic Artery

Axial and coronal CT images with intravenous contrast demonstrate a left persistent sciatic artery (long arrows) coursing through the greater sciatic notch and deep to the gluteus maximus muscle. Note the asymmetrically diminutive left external iliac artery (short arrows)

  • A persistent sciatic artery (PSA) is a rare vascular anomaly in which the internal iliac artery courses through the greater sciatic notch and in to the thigh
    • During embryonic development, the sciatic artery usually involutes as the femoral artery develops
    • Recognition of an unusually enlarged internal iliac artery and a diminutive external iliac artery are some clues in diagnosing a PSA
    • The PSA course runs close to the sciatic nerve, and can run within the nerve sheath in some cases
    • Distally, the PSA runs deep to the gluteus maximus muscle, coursing along the adductor magnus muscle
  • Reported in up to 0.03-0.06% of the population and can be bilateral in 20% of cases
  • PSA is considered complete when it is the dominant blood supply to the popliteal artery and incomplete with the femoral artery is the dominant blood supply to the popliteal artery
  • 5 types have been described:
    • type 1 is a complete PSA with a normal femoral artery
    • type 2 is a complete PSA with a incompletely developed femoral artery
    • type 3 is a incomplete PSA (only the cephalic portion is present) and normal femoral artery
    • type 4 is a incomplete PSA (only the caudal portion is present) and normal femoral artery
    • type 5 is when the PSA arises from the median sacral artery
  • Majority (80%) become symptomatic at some point presenting with intermittent claudication, ischemia, pulsatile mass or neurologic symptoms
  • Susceptible to repetitive trauma from sitting and hip flexion/extension
    • Results in premature atherosclerosis and aneurysm formation
    • Aneurysm found in 48%, and stenosis and occlusion of the PSA in 7% and 9%, respectively
  1. Mcquaid M, Gavant ML. Posttraumatic pseudoaneurysm of a persistent sciatic artery. AJR Am J Roentgenol. 1995;164 (6): 1514-5. 
  2. Pillet J, Albaret P, Toulemonde JL, Cronier P, Raimbeau G, Chevalier JM. Tronc arteriel ischiopoplite, persistance de l’artere axiale. Bull Assoc Anat 1980;64:109e22.
  3. Pillet J, Cronier P, Mercier Ph, Chevalier JM. The ischio popliteal arterial trunk: a report of two cases. Anat Clin 1982; 3:329e31. 
  4. Gauffre S, Lasjaunias P, Zerah M. Sciatic artery: a case, review of literature and attempt of systematization. Surg Radiol Anat 1994;16(1):105e9.
  5. Bower EB, Smullens SN, Parke WW. Clinical aspect of persis- tent sciatic artery: report of two cases and review of the literature. Surgery 1977;81(5):588e95.