|Year : 2022 | Volume
| Issue : 1 | Page : 118-121
Dumbbell type large prostatic urethral calculus: Sonographic diagnosis
Bhavik Unadkat, Suresh Vasant Phatak, Nishant Raj, Pratik Bhansali
Department of Radio Diagnosis, Jawaharlal Nehru Medical College, Wardha, Maharashtra, India
|Date of Submission||11-Nov-2021|
|Date of Decision||18-Jan-2022|
|Date of Acceptance||26-Feb-2022|
|Date of Web Publication||25-Jul-2022|
Dr. Suresh Vasant Phatak
Department of Radio Diagnosis, Jawaharlal Nehru Medical College, Sawangi (Meghe), Wardha - 442 001, Maharashtra
Source of Support: None, Conflict of Interest: None
Massive calculi in the prostatic urethra are even more unusual than calculi in the urethra. The size, form, and location of the calculus, as well as the state of the urethra, all impact the therapeutic method. If the stone is big and obstinate, it can be removed using perineal or suprapubic methods. A case report of a patient who had difficulty in passing urine and burning during micturition is presented. Two calculi were found in the urinary bladder: One was vesical calculus, and the other was vesicourethral (prostatic) dumbbell-shaped calculus, as observed on ultrasonography.
Keywords: Sonography, urethral calculus, urinary calculus
|How to cite this article:|
Unadkat B, Phatak SV, Raj N, Bhansali P. Dumbbell type large prostatic urethral calculus: Sonographic diagnosis. J Datta Meghe Inst Med Sci Univ 2022;17:118-21
|How to cite this URL:|
Unadkat B, Phatak SV, Raj N, Bhansali P. Dumbbell type large prostatic urethral calculus: Sonographic diagnosis. J Datta Meghe Inst Med Sci Univ [serial online] 2022 [cited 2022 Aug 18];17:118-21. Available from: http://www.journaldmims.com/text.asp?2022/17/1/118/352238
| Introduction|| |
Urinary calculi are the third most frequent urinary tract illness, behind urinary tract infections and prostate pathologic diseases. In the genitourinary tract, urethral calculi account for 1%–2% of all calculi. Urethral strictures, diverticula, and a posterior urethral valve are all common causes of urinary calculi. It is rare to find big calculi in the prostate's urethra. There have only been a few cases of large prostatic urethral calculi documented in the literature.
| Case Report|| |
A 35-year-old man presented with reduced urinary stream, straining during micturition, and dysuria for 2-month duration. He had no previous history of hematuria, fever, vomiting, or trauma, although he did have the sensation of incomplete emptying of the urinary bladder. On physical examination, external genitalia appeared to be normal. Hematology: Complete blood count, renal function tests, liver function tests, serum electrolytes, serum parathyroid hormone, and serum calcium levels were within normal limits. Urine routine and microscopy: traces of albumin and 3–4 Red blood cells and plenty of pus cells/high-power field were seen. The patient was referred for abdominal sonography. Ultrasound abdomen revealed a classical dumbbell-shaped calculus in the urethra and urinary bladder connected by a narrow isthmus [Figure 1]. Another separate calculus was also seen inside the urinary bladder cavity [Figure 2]. A radiograph of the pelvis confirmed both ultrasonography findings [Figure 3].
|Figure 1: Gray scale ultrasound image showing a classical dumbbell-shaped calculus in urethra and urinary bladder connected by narrow isthmus|
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|Figure 2: Gray scale ultrasound image showing echogenic calculus in the urinary bladder causing posterior acoustic shadowing|
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|Figure 3: Radiograph of KUB region showing dumbbell-shaped calculi in bladder and prostatic urethra and another separate vesical calculus. KUB: Kidney, ureter and bladder|
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| Discussion|| |
The male urethra is roughly 17–20 cm long and is separated into two portions at the anterior and posterior ends of each segment. According to clinical and imaging findings, the anterior urethra is traditionally divided into penile or pendulous and bulbous parts at the penoscrotal junction. The pendulous portion terminates in the glans penis to form the fossa navicularis, which is 1–2 cm long. The anterior urethra also extends from the external meatus to the inferior edge of the congenital diaphragm coursing through the corpus. The anterior urethra has periurethral Littre glands, which are more numerous in the dorsal aspect of the penile urethra, and in the bulbous urethral sump, the Cowper glands are two pea-sized glands that lie within the urogenital diaphragm on each side of the bulb. The bulbous urethra assumes a conical shape just proximally to the sump and is known as bulbous. The posterior urethra is divided into the prostatic and membranous urethras. The prostatic urethra is approximately 3.5 cm long and passes through the prostate slightly anterior to the midline. On the posterior wall of the posterior urethra, a longitudinal ridge of smooth muscle extends from the bladder neck to the membranous urethra. This longitudinal ridge then continues into the verumontanum, an ovoid mount that lies in posterior wall, within the middle of verumontanum lies a prostatic utricle a small saccular discouragement that is a minimal remainder of Mullerian channel fair distal and horizontal to the utricle are the openings of the matched ejaculatory conduit, the prostatic organs purge specifically into the prostatic urethra by means of different little openings that encompass the verumontanum, the prostatic urethra at that point tappers distally into the membranous urethra which is roughly 1–2 cm long and closes at the second rate angle of urogenital stomach. Most of the urethral calculi comprise little stones removed from the bladder into the urethra amid voiding and are alluded to as transient calculi sometimes be that as it may a stone possibly expansive sufficient to gotten to be held up at a point of urethral narrowing such as membranous urethra, rarely essential arrangement of stone happens within the urethra, when stricture is display or it may be show with urethral diverticulum, indications of urethral calculi counting powerless stream, dysuria. Retrograde urethrography will usually depict a rounded filling defect in the urethra, on preprocedural lower abdominal radiograph, this stone may be identified before contrast material is injected.
Calcium, magnesium ammonium phosphate, uric acid, cystine, and medicines and their metabolites are the five main kinds of urinary calculi. Calcium containing calculi approximate frequency is 70%–80% responsible factors include primary hyperparathyroidism, chronic diarrhea, and distal renal tubular acidosis and they show wide range of density and gross morphology on imaging, calcium ammonium phosphate (struvite calculi) is 15%–20% in frequency and is mainly caused by infection and on imaging, they are seen as staghorn calculus which refers to a calculus involving renal pelvis and extending into at least two calyces, uric acid calculi are 5%–10% in frequency and seen with gout, small bowel disease, and high body mass index, and on imaging, they are radiolucent on radiography, cystine calculi are seen in 1%–3% of cases mainly associated with cystinuria, and on imaging, these calculi may contain low attenuation foci on computed tomography (CT), least common of all calculi are related to some medication and their metabolites caused by prolonged or excessive use of some medication, and on imaging, indinavir can be radiolucent even on CT. The various modalities which are used in the evaluation of urolithiasis include radiography, excretory urography, ultrasound, magnetic resonance (MR) urography, unenhanced CT, and dual-energy CT (DECT). Radiography has an advantage as it contains low radiation dose with respect to CT and about 90% of calculi are radiopaque, the disadvantage with radiography is only about 60% sensitivity in the detection of urinary calculi; and the source for the patient's pain may not be always urolithiasis so the preferred utilization of radiography is for monitoring of calculus burden in the patient known to suffer from urolithiasis. Excretory urography has its own advantage that being in the delineation of renal and collecting system anatomy, the disadvantage with excretory urography is that there is exposure to a contrast agent and the duration of examination is long and sometimes, the contrast agent can mask the calculi. CT is now preferred over excretory urography in most settings for the evaluation of renal and collection system anatomy. Ultrasound has its own advantage as it lacks the ionizing radiation and has intermediate sensitivity for the detection of renal calculi and hydronephrosis, disadvantage with ultrasound is its operator dependent and the deep portions of the ureter are difficult to the image is masked by bowel shadows sometimes. Pregnant women and pediatric patients among these recurrent stone formers can be the target for utilization of ultrasound. MR urography has advantage in terms of nonionizing radiation and it can be also used in imaging of secondary effects of urolithiasis and other genitourinary abnormalities, including neoplastic etiology. Disadvantage with MR urography is that actual calculus is difficult to visualize so MR urography per say can be used in the evaluation of urinary tract findings other than urolithiasis such as a stricture. Unenhanced CT has its advantage that being a delineation of the urinary tract and nongenitourinary anatomy, rapid acquisition, and interpretation can be done. Disadvantage with unenhanced CT includes radiation exposure, especially in recurrent stone former, young or pregnant patient, unenhanced CT can be utilized as a first-line investigation in an adult with flank pain. The pathogenesis of calculus formation includes a number of factors. The factors that put a patient at risk of developing renal calculi are mostly unknown. The concept of urine supersaturation is critical to calculus formation hypotheses. When a solution has more dissolved material than it can hold, supersaturation occurs, which can lead to the formation of metabolite crystals. The composition of urinary calculi has been linked to supersaturation values. Calcium oxalate calculi are the most frequent calcium-based calculi, accounting for 60% of all calcium-based calculi. Stones trapped in the posterior urethra are divided into three groups by Barrett JC.
- The Vesicourethral System's Stones – These stones are partly in the posterior urethra and partly in the bladder, and therefore, astride the internal sphincter, which causes the constriction shown on the calculus
- Urethral Stones – found in the urethra proper
- Stones in the urethra and prostate. On gray-scale imaging, these stones are partially embedded in the prostate gland's preformed cavity. The narrowband intrinsic machine noise is assumed to be the cause of the twinkle artifact.
Ultrasound can identify calculi as tiny as 0.5 mm, which appear in the urinary system as echogenic foci with shadowing. Color Doppler imaging can be used to check the visualization of calculus by eliciting a twinkling artifact in the expected shadowing region on gray-scale imaging. The narrowband intrinsic machine noise is assumed to be the cause of the twinkle artifact.
An important aspect of preoperative evaluation, therapy, and stone recurrence, prevention is determining the makeup of the urinary calculi. DECT uses the attenuation difference produced by two different X-ray energy spectra to quantify urinary calculi composition as uric acid and nonuric acid while still providing the information associated with a conventional CT. Before the introduction of DECT, available methods for determining urinary stone composition were only available after stone extraction and were unable to aid in optimized stone management before intervention.
The sensitivity and the specificity in distinguishing uric acid from nonuric acid calculi were 100% and 96% approximately.
According to the literature, over 60% of individuals with chronic urethral stricture illness have prostate calculi. Prostatic calculi are frequently identified in association with urethral stricture disease or urethral blockage. These calculi gradually grow into enormous ones as more calcium phosphates are deposited in the prostatic urethra. They can also result in the production of bladder stones due to urine stasis if untreated. The location, size, and presence of any accompanying secondary stones all affect how a massive prostatic calculus is managed. Radical prostatectomy, open retropubic prostatolithotomy, and endoscopic lithotripsy are a few of the treatments for large calculi. Typical symptomatic calculi usually do not require surgical intervention, however, in cases of severe symptoms, complete elimination is preferred, several treatment options based on the stone location and size such as endoscopic lithotripsy and open prostatolithotomy are recommended, prostatic calculi which protrude in urethra causing urinary retention could be removed transurethrally, endoscopic removal consist of stone extraction through the resectoscope loop and transurethral resection of prostatic tissue with stones. Transurethral removal offers relief in symptoms but complete removal of calculus and prevention of new calculus formation maybe difficult to achieve. In older patients with multiple large stones or a single large stone, open prostatolithotomy is recommended.
For more than 100 years, now the retrograde and voiding cystourethrography have been used in imaging of male urethra. Voiding cystourethrography a test to assess male urethra includes acquiring an X-ray after having the bladder filled with contrast before imaging. This technique was first described in the late 1960 and is still a gold standard in the diagnosis of urethral disorder. This process has many advantages including ease of execution and its ability for the assessment of entire urethra. Sonourethrography technique includes cleaning of meatus and insertion of Foleys catheter into the distal segment of the urethra to stabilize the catheter at the level of fossa navicularis, the catheters balloon is filled to a volume of 2 ml for delivering fluid to urethra 20–100 ml of sodium chloride 0.9% is injected with a syringe through the catheter. The linear probe is used for the technique and the transducer is placed lengthways on the ventral region of the penis and then moved transcrotally and transperineally to visualize the bulbar urethra, due to the short distance between the urethra and skin, the highest possible frequencies to be used to obtain the most accurate image. In an ultrasound, the picture is similar to calculus in other parts of the urinary tract, it is seen as hyperechoic structure sometimes mobile, localized to the urethral lumen giving acoustic shadowing and on color Doppler showing a twinkling artifact. One of the main problems when performing sonourethrogram is air bubbles develop during fluid intake, they may simulate small calculi leading to a false diagnosis.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
| Conclusion|| |
Dumbbell-type large prostatic urethral calculus is a rare entity. Asymptomatic nature of prostatic calculi may lead to misdiagnosis while assessing patients with lower urinary tract symptoms. Sonography can be a noninvasive highly accurate and cost-effective imaging modality helping early diagnosis and can play an important role in the clinical management of the patient.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]