Figure 1
Axial fused PET/CT image
An intensely hypermetabolic 2 cm area (arrow) anterior and slightly to the left of midline at the level of the vagina was initially concerning for MMMT local recurrence.
Urethral diverticulum: A mimicker of malignancy
SectionUroradiology & genital male imaging
Case TypeAnatomy and Functional Imaging
AuthorsJoyce Hsu BS1, Leo Jia BA1, Darko Pucar MD PhD2, Kandace Klein DO3, Hadyn Williams MD2
Connected authors
71 years, female
Clinical History
A 71-year-old female patient with a history of previously treated uterine malignant mixed Mullerian tumour (MMMT) underwent 18fludeoxyglucose (18FDG)-PET/CT for initial treatment planning of newly diagnosed invasive ductal carcinoma of the right breast.
Imaging Findings
The 18FDG-PET/CT scan showed intense focal uptake (SUVmax 14.7) in the left anterolateral periurethral region at the level of the vagina that mimicked MMMT local recurrence (Fig. 1), and neither unenhanced CT performed with PET (Fig. 2) nor prior contrast-enhanced CT (not shown) demonstrated a corresponding urethral diverticulum. However, further evaluation done with T2-weighted MRI pelvis revealed a focal area of high signal intensity surrounding the urethra consistent with a urethral diverticulum, excluding MMMT recurrence (Fig. 3) [1].
Discussion
Background
Female urethral diverticula are rare, benign outpouchings of the urethra into the periurethral fascia. The classic symptoms manifest as a triad of D’s: dysuria (urinary tract infection), dyspareunia, and dribbling (urinary incontinence). However, these symptoms are nonspecific and found in only one third of cases.
Clinical Perspective
Urethral diverticula are often asymptomatic, incidentally detected, or misdiagnosed, thus posing diagnostic radiology challenges, specifically in PET/CT interpretation. The patient in this case did not have any of the classic symptoms associated with urethral diverticulum prior to receiving the 18FDG-PET/CT scan. The requesting physician was therefore notified that an area of high 18FDG avidity was concerning for MMMT local recurrence and contrast MRI was advised.
Imaging Perspective
The classic appearance of an urethral diverticulum on unenhanced CT performed with PET is an area of low-attenuation with increased metabolic activity [2]. Postvoid T2-weighted MRI pelvis is the ideal imaging examination for urethral diverticulum diagnosis as there are variable appearances on other radiologic studies [3, 4]. The case presented here is one such example, where the clinical history and 18FDG-PET/CT suggested MMMT local recurrence, but later evaluation with T2-weighted MRI excluded this differential diagnosis.
Outcome
Therapeutic options include various surgical interventions, such as transvaginal diverticulectomy or urethral reconstruction. If asymptomatic, urethral diverticulum does not always indicate surgical excision [5]. In this case, the patient presented asymptomatically and chose to forgo such operations.
Take Home Message, Teaching Points
Urethral diverticulum is an uncommon condition that is often incidentally detected or misdiagnosed. This atypical presentation of urethral diverticulum on 18FDG-PET/CT scan demonstrates the superiority of postvoid T2-weighted MRI pelvis over other radiographic studies in diagnosing urethral diverticulum.
Female urethral diverticula are rare, benign outpouchings of the urethra into the periurethral fascia. The classic symptoms manifest as a triad of D’s: dysuria (urinary tract infection), dyspareunia, and dribbling (urinary incontinence). However, these symptoms are nonspecific and found in only one third of cases.
Clinical Perspective
Urethral diverticula are often asymptomatic, incidentally detected, or misdiagnosed, thus posing diagnostic radiology challenges, specifically in PET/CT interpretation. The patient in this case did not have any of the classic symptoms associated with urethral diverticulum prior to receiving the 18FDG-PET/CT scan. The requesting physician was therefore notified that an area of high 18FDG avidity was concerning for MMMT local recurrence and contrast MRI was advised.
Imaging Perspective
The classic appearance of an urethral diverticulum on unenhanced CT performed with PET is an area of low-attenuation with increased metabolic activity [2]. Postvoid T2-weighted MRI pelvis is the ideal imaging examination for urethral diverticulum diagnosis as there are variable appearances on other radiologic studies [3, 4]. The case presented here is one such example, where the clinical history and 18FDG-PET/CT suggested MMMT local recurrence, but later evaluation with T2-weighted MRI excluded this differential diagnosis.
Outcome
Therapeutic options include various surgical interventions, such as transvaginal diverticulectomy or urethral reconstruction. If asymptomatic, urethral diverticulum does not always indicate surgical excision [5]. In this case, the patient presented asymptomatically and chose to forgo such operations.
Take Home Message, Teaching Points
Urethral diverticulum is an uncommon condition that is often incidentally detected or misdiagnosed. This atypical presentation of urethral diverticulum on 18FDG-PET/CT scan demonstrates the superiority of postvoid T2-weighted MRI pelvis over other radiographic studies in diagnosing urethral diverticulum.
Differential Diagnosis List
Urethral diverticulum
Malignant mixed Mullerian tumour (MMMT)
Excreted FDG
Final Diagnosis
Urethral diverticulum
References
[1] Singla P, Long S, Long C, et al. (2013) Imaging of the female urethral diverticulum. Clinical Radiology Volume 68, pages e418–e425 (PMID: 23561897)
[2] Chou CP, Levenson RB, Elsayes KM, et. al. (2008) Imaging of Female Urethral Diverticulum: An Update. Radiographics Volume 28, pages 1917-1930 (PMID: 19001648)
[3] Romanzi LJ, Groutz A, Blaivas JG (2000) Urethral diverticulum in women: diverse presentations resulting in diagnostic delay and mismanagement. The Journal of Urology Volume 164, pages 428-433 (PMID: 10893602)
[4] Greenwell TJ, Spilotros M (2015) Urethral diverticula in women. Nature Reviews Urology Volume 12, pages 671-680 (PMID: 26458752)
[5] Foley CL, Greenwell TJ, Gardiner RA (2011) Urethral diverticula in females. BJU International Volume 108, pages 20-23 (PMID: 22085121)
Case information
| URL: | https://www.eurorad.org/case/13959 |
| DOI: | 10.1594/EURORAD/CASE.13959 |
| ISSN: | 1563-4086 |
License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Figure 2
Axial unenhanced CT image
Unenhanced CT performed with PET scan used for comparison did not demonstrate corresponding urethral diverticulum.
Figure 3
Axial T2-weighted MRI image
A focal area of high signal intensity surrounding the urethra is consistent with an urethral diverticulum (arrow).
Axial fused PET/CT image
An intensely hypermetabolic 2 cm area (arrow) anterior and slightly to the left of midline at the level of the vagina was initially concerning for MMMT local recurrence.
Pucar D, Department of Radiology & Imaging, Nuclear Medicine Section, Medical College of Georgia, Augusta University, USA
Pucar D, Department of Radiology & Imaging, Nuclear Medicine Section, Medical College of Georgia, Augusta University, USA
Axial unenhanced CT image
Unenhanced CT performed with PET scan used for comparison did not demonstrate corresponding urethral diverticulum.
Pucar D, Department of Radiology & Imaging, Nuclear Medicine Section, Medical College of Georgia, Augusta University, USA
Pucar D, Department of Radiology & Imaging, Nuclear Medicine Section, Medical College of Georgia, Augusta University, USA
Axial T2-weighted MRI image
A focal area of high signal intensity surrounding the urethra is consistent with an urethral diverticulum (arrow).
Klein K, Department of Radiology & Imaging, Body Imaging Section, Medical College of Georgia, Augusta University, USA
Klein K, Department of Radiology & Imaging, Body Imaging Section, Medical College of Georgia, Augusta University, USA