MR and CT appearance of urethral clear cell adenocarcinoma in a woman

Clear Cell Adenocarcinoma of the Urethra in Women: Distinctive MRI Findings for Differentiation From Nonadenocarcinoma and Non-Clear Cell Adenocarcinoma of the Urethra

OBJECTIVE

The purpose of this study is to evaluate the MRI findings differentiating clear cell adenocarcinoma of the urethra (CCAU) from nonadenocarcinoma of the urethra (NACU) and non-clear cell adenocarcinoma of the urethra (NCCAU) in women.

MATERIALS AND METHODS

Six women with pathologically proven CCAU, six women with pathologically confirmed NACU (two squamous cell carcinomas and four transitional cell carcinomas), and nine women with NCCAU underwent preoperative MRI. The MRI findings for CCAU, NACU, and NCCAU were reviewed by a radiologist who was blinded to the histopathologic findings and were compared using the Mann-Whitney U test and the Fisher exact test.

RESULTS

CCAU was shorter in height than NACU (3.4 cm vs 5.5 cm; p = 0.020) and also had a smaller height-to-width ratio than NACU (0.85 vs 1.51; p < 0.001) and NCCAU (0.85 vs 1.48; p = 0.002). The proportion of preserved urethra in CCAU (67%) was larger than that in either NACU (9%; p < 0.001) or NCCAU (22%; p < 0.001). All cases of CCAU originated within a diverticulum, whereas none of the cases of NACU and only one NCCAU originated in a diverticulum. Intratumoral septation was more frequently observed in CCAU (100%) than in NACU (16.6%; p = 0.015) or NCCAU (11.1%; p = 0.001).

CONCLUSION

MRI findings for CCAU were significantly distinctive, compared with findings for NACU and NCCAU. All cases of CCAU were associated with a urethral diverticulum, and CCAU had a lower height-to-width ratio, more frequent intratumoral septation, and greater preservation of normal urethra than did NACU and NCCAU.

Clear cell adenocarcinoma of the urethra: 18F-FDG PET/CT imaging

Clear cell adenocarcinoma of the urethra is a rare and aggressive tumor of female gender preponderance. This neoplasm, the origin of which is still widely debated, has been reported with CT and MRI in case reports and small series. To the previously published conventional cross-sectional imaging description, the authors add the PET/CT features of this uncommon urologic neoplasm at its advanced stage in a 60-year-old patient complaining of urinary retention.

Magnetic resonance imaging of solid urethral and peri-urethral lesions

Solid urethral and peri-urethral lesions are rare and encompass benign and malignant aetiologies. A diagnosis without imaging is often challenging secondary to non-specific clinical symptoms and overlapping findings at the time of physical examination. Magnetic resonance (MR) imaging may be helpful in confirming a diagnosis while providing anatomical detail and delineating disease extent. This article reviews the normal MR anatomy of the male and female urethra, the MR appearance of solid primary and secondary urethral lesions, and the MR appearance of solid urethral lesion mimics.

Teaching points

• MRI is an important imaging technique in the evaluation of the spectrum of solid urethral lesions.

• With excellent soft tissue resolution, MR is accurate in staging primary urethral carcinoma.

• Disruption of the zonal anatomy of the female urethral wall indicates peri-urethral extension.

• Be aware of benign urethral lesions, particularly those that may mimic solid urethral masses.

Clear cell carcinoma of female urethral diverticulum--a case report

Primary malignancies of female urethral diverticulum are rare. A well-documented female patient with primary clear cell carcinoma of the urethral diverticulum is presented here. A 65-year-old woman presented with frequency and voiding difficulty for 2 months. Physical examination showed a 4-cm mass protruding from anterior vaginal wall. Intravenous urography, magnetic resonance imaging, and cystoscopy showed a polypoid mass in urethral diverticulum. She then underwent anterior exenteration with ileal conduit diversion and urethrectomy. Pathology confirmed the diagnosis of clear cell adenocarcinoma with bladder neck invasion. She had no disease recurrence at 2-year follow-up. Careful clinical examination and image studies are helpful in making the preoperative diagnosis for the rare disease. Early radical surgery can achieve better survival.

Imaging of unusual perineal masses

OBJECTIVE

The purpose of this article is to describe the radiologic features of unusual tumors that occur in the perineum.

CONCLUSION

The perineal space is often overlooked because of the infrequency of abnormalities. Accurate image interpretation and visualization of extent of pathology is important for proper management. Trauma and infectious diseases occur in the acute setting, whereas tumors are common in the chronic setting. Cross-sectional imaging plays a crucial role in depicting perineal anatomy and evaluating the extent of disease.

Cross-sectional imaging of the female urethra: technique and results

Clinical assessment of women with urethral symptoms is difficult, necessitating further evaluation with imaging. Urethrography provides limited information on luminal abnormalities of the urethra. Recent advances in ultrasound (US) and magnetic resonance (MR) imaging have dramatically improved evaluation of the female urethra, clarifying findings at physical examination and providing accurate road maps for surgeons. High-resolution transvaginal US, transperineal US, and transurethral US are reliable techniques for diagnosis and characterization of urethral abnormalities. High-resolution multiplanar MR imaging with phased-array pelvic and endovaginal coils demonstrates the urethral anatomy in greater detail. In women with urethral diverticula, US and MR imaging demonstrate the number of diverticula and the location, size, configuration, and possible contents of the sac. Most important, the position of the neck of the diverticulum may be identified for the surgeon. Imaging features do not allow differentiation between histologic subtypes of urethral carcinoma; the diagnosis is established with histopathologic examination. Periurethral cysts do not communicate with the urethra and therefore can often be differentiated from urethral diverticula at endocavitary MR imaging. High-resolution multiplanar US and MR imaging allow comprehensive evaluation of abnormalities of the female urethra.

Imaging of urethral disease: a pictorial review

Retrograde urethrography and voiding cystourethrography are the modalities of choice for imaging the urethra. Cross-sectional imaging modalities, including ultrasonography, magnetic resonance (MR) imaging, and computed tomography, are useful for evaluating periurethral structures. Retrograde urethrography is the primary imaging modality for evaluating traumatic injuries and inflammatory and stricture diseases of the male urethra. Sonourethrography plays an important role in the assessment of the thickness and length of bulbar urethral stricture. Although voiding cystourethrography is frequently used to evaluate urethral diverticula in women, MR imaging is highly sensitive in the demonstration of these entities. MR imaging is also accurate in the local staging of urethral tumors.

MR imaging of the male and female urethra

Conventional radiographic contrast material-enhanced studies (eg, retrograde urethrography [RUG], voiding cystourethrography [VCUG], double-balloon catheter urethrography) and ultrasonography are useful in evaluating the anatomy of the urethra but are limited in demonstrating anatomic derangement of adjacent structures. Since the anatomic details of both the urethra and periurethral tissues can be evaluated noninvasively with magnetic resonance (MR) imaging, this modality can be used as an adjunctive tool for evaluation of urethral abnormalities. In patients with congenital anomalies, MR imaging is reserved for cases of intersex anomalies or complex genitourinary anomalies, in which evaluation of internal organs is essential. MR imaging may demonstrate diverticula that are not seen on radiographic contrast-enhanced studies, including VCUG, RUG, or double-balloon catheter study. In cases of inflammation, MR imaging can demonstrate not only inflammatory infiltration around the urethra but also the presence of a periurethral abscess or sinus tract. In cases of trauma, MR imaging is helpful in assessing the presence and extent of anterior or posterior urethral injury and predicting the occurrence of complications. At MR imaging, a fistula can be seen as a direct communicating channel with an adjacent organ. In patients with urethral tumors, the major role of MR imaging is in local staging.