Scrotal Calculi. Article. Hakan Artas, MD, Irfan Orhan, MD

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1 Article Scrotal Calculi Hakan Artas, MD, Irfan Orhan, MD Objective. Scrotal calculi are freely mobile calcified bodies lying between the layers of the tunica vaginalis of the testes. The etiology of scrotal calculi is unclear. They may develop as a sequela to hematomas or inflammatory changes within the scrotum or loose bodies from torsion and infarction of the appendix testis or epididymis. The aim of our series was to examine the etiopathogenesis of scrotal calculi, which were detected incidentally in various age groups, with reference to the medical literature. Methods. Among 868 patients, 23 (2.65%) cases of scrotal calculi were diagnosed on sonographic examinations. The ages of the patients ranged between 4 months and 65 years (mean age ± SD, 28.3 ± 11.9 years). Results. On sonographic examination; we found a total of 51 scrotal calculi with a mean size of 4.22 ± 2.42 mm (range, 2 10 mm) in 23 patients, an epididymal cyst in 3 patients (13%), epididymitis in 2 patients (8.6%), hydrocele in 3 patients (13%), varicocele in 3 patients (13%), and testicular microlithiasis in 1 patient (4%). Scrotal calculi were solitary in 11 patients and multiple in 12 patients. Conclusions. The prevalence of scrotal calculi was 2.65%, and a minority of patients had other abnormalities, reflecting the generally benign etiology of these pearls. To date, no information is available in the literature about the results of chronic irritation due to scrotal calculi. Further studies in larger series need to be performed to elucidate the formation mechanism and natural course of scrotal calculi. Key words: calculi; scrotum; sonography. Received July 16, 2007, from the Department of Radiology, Elazig Training and Research Hospital, Elazig, Turkey (H.A.); and Department of Urology, Firat University, Faculty of Medicine, Elazig, Turkey (I.O.). Revision requested July 30, Revised manuscript accepted for publication August 15, Address correspondence to Hakan Artas, MD, Elazig Egitim ve Arastirma Hastanesi, Radyoloji Bölümü, Elazig, Turkey. [email protected] The intrascrotal calculus was first described during surgery by Kickham 1 in 1935 as a fibrinoid loose body or scrotal pearl. Scrotal calculi are benign entities, which are thought to represent freely mobile calcified bodies lying between the layers of the tunica vaginalis of the testes. The etiology of scrotal calculi is unclear. They may develop as a sequela to hematomas or inflammatory changes within the scrotum or loose bodies from torsion and infarction of the appendix testis or epididymis. The literature on intrascrotal lithiasis consists mostly of case reports. 1 4 However, some recent studies revealed that the prevalence of scrotal calculi was very high in some specific populations. 5 8 The aim of our series was to examine the etiopathogenesis of scrotal calculi, which were detected incidentally in various age groups, with reference to the medical literature by the American Institute of Ultrasound in Medicine J Ultrasound Med 2007; 26: /07/$3.50

2 Scrotal Calculi Materials and Methods Scrotal sonographic examinations were performed on 868 patients referred from urologic and surgical clinics at Elazig Training and Research Hospital between March 2006 and June Twenty-three cases of scrotal calculi were diagnosed on sonographic examinations at the radiology clinic. In all examinations we used an SSD-4000 device (Aloka Co, Ltd, Tokyo, Japan) equipped with a 5- to 10-MHz linear probe. The examinations were performed with patients lying in the supine position. The scrotum was immobilized by placing a towel between the thighs. Minimal pressure was applied with the transducer, and no water bath was used. Longitudinal, transverse, and oblique scans were obtained in all cases. Patients were evaluated for the presence of scrotal abnormalities such as scrotal calculi, hydrocele, and testicular and epididymal cysts and calcifications as well as inhomogeneity of the testicular and epididymal parenchymal echo texture. After detection of scrotal calculi on sonography, all patients were reevaluated clinically by a urologist in the urology clinic for the presence of scrotal pain, discomfort, trauma, inflammation, swelling, or masses. Results Among the 868 patients, 51 scrotal calculi in 23 (2.65%) patients were identified. The ages of these 23 patients ranged between 4 months and 65 years (mean age ± SD, 28.3 ± 11.9 years), and clinical findings included scrotal swelling, scrotal pain, varicocele, and infertility. A total of 23 patients were referred for sonographic examination for scrotal pain (n = 6), varicocele (n = 3), scrotal swelling (n = 6), infertility (n = 2), and a combination of these conditions (n = 6). The initial physical examinations of the 23 patients revealed scrotal swelling due to hydrocele (n = 3), an epididymal mass (n = 3), and epididymal thickening (n = 2), with the remaining having no abnormalities. In none of the patients were scrotal calculi detected on the first routine physical examination. None of the patients had anamnesis of scrotal microtraumas related to prolonged cycling or riding. On sonographic examination, 12 (52.1%) of 23 patients had no pathologic abnormalities of the scrotal contents except for scrotal calculi. We found a total of 51 scrotal calculi with a mean size of 4.22 ± 2.42 mm (range, 2 10 mm) in the 23 patients (Figures 1 and 2), an epididymal cyst (2 on the contralateral side and 1 on the ipsilateral side) in 3 patients (13%), epididymitis (2 on the bilateral side and 1 on the ipsilateral side) in 2 patients (8.6 %), hydrocele (2 on the contralateral side and 1 on the ipsilateral side) in 3 patients (13%), varicocele (1 on the contralateral side and 2 on the ipsilateral side) in 3 patients (13%), and testicular microlithiasis in 1 patient (4%; Figure 3). Scrotal calculi were solitary in 11 patients and multiple in 12 patients. Patient histories and clinical and sonographic findings in the 23 cases are summarized in Table 1. Sonography depicted the calculi typically as round or oval echogenic foci with or without acoustic shadowing in cases of large and small calculi, respectively. When patients changed their positions, all echogenic foci moved away from the tunica vaginalis testis. Movement of the calculi depended on their size and the amount of scrotal fluid. The larger the calculus, the less it moved. Figure 1. Scrotal calculus in a 65-year-old patient with bilateral epididymitis. In this patient, appendix testes were not visualized. Longitudinal sonography of the testis (T) shows extratesticular echogenic calculi (arrow) with posterior acoustic shadowing. There is minimal fluid (F) in the tunica vaginalis testis J Ultrasound Med 2007; 26:

3 Artas and Orhan Figure 2. Transverse sonography shows echogenic calculi (arrow) with posterior acoustic shadowing (arrowheads) in a 17-year-old patient. T indicates testis. Discussion Figure 3. Longitudinal sonography shows echogenic calculi of limited testicular microlithiasis of the left testis (arrowheads) and 2 echogenic calculi (arrows) in the left hemiscrotum in a 29-yearold patient. Scrotal calculi are usually accidentally found during surgery or routine sonographic examination. They may be detected on palpation by the patients themselves, and they may prove painful after repeated patient palpation. 9 Sonography is the ideal method to use in diagnosing scrotal calculi. 2 Stones are easily defined by sonography because of the hyperechoic nature of the calcification, which causes a discrete acoustic shadow. With sonography, calculi in hydrocele can be seen moving in the fluid between the tunicae, a feature that differentiates them from calculi in cystoceles 10 and urethroscrotal fistulas 11 and from other scrotal calcifications. 12 The etiology of scrotal calculi is unclear. They may result from torsion of the appendix testis or the epididymis, from hematomas, or from inflammation of the tunica vaginalis testis. 2 Inflammation may damage the tunica vaginalis testis layers, their lymphatic vessels, and other soft tissues of the scrotum and spermatic cord, leading to fibrosis. 2,12 These changes create a sieve effect; that is, small water molecules can pass through the fibrotic tunica vaginalis testis membranes and narrow lymphatic vessels, but larger molecules of cholesterol, calcium compounds, fibrin, and hydroxyapatite cannot. Calculi result from the buildup of these deposits. 6 An appendix testis or epididymis that has twisted and become free has also been postulated as a cause of scrotal calculi. 2 The natural history of torsion of an appendix is normally that the symptoms settle, and the twisted appendix atrophies. This may be followed with repeated sonographic examinations, but that is not really necessary. There are suggestions that these twisted appendixes calcify and become scrotoliths. 13 This is thought to be unlikely because acute severe symptoms, commonly associated with infarction, are not described with a scrotal calculus, and multiple scrotal calculi described in the literature cannot be explained on this basis. 11,14 In our study, the scrotal calculi were solitary in 11 patients. We think that the hypothesis of a twisted appendix testis may be appropriate in 11 of 23 patients. Repeated microtraumas may be risk factors for development of scrotal calculi. In a study by Frauscher et al, 5 85 extreme mountain bikers, who did a minimum of 2 hours per day, 6 days per week of off-road biking and had covered a distance of greater than 5000 km with their mountain bikes annually, were investigated. Most of these subjects also had other scrotal abnormalities in addition to calculi, which may have been a result of repeated chronic micro- J Ultrasound Med 2007; 26:

4 Scrotal Calculi Table 1. Histories and Clinical and Sonographic Findings in 23 Cases Additional Case Age, y Clinical Findings Calculi, n Calculi Size, mm* Sonographic Findings 1 40 Scrotal swelling 1 4 None 2 26 Varicocele, scrotal pain None 3 23 Scrotal pain None 4 26 Right scrotal swelling Contralateral (right) epididymal cyst 5 19 Scrotal pain None 6 21 Scrotal pain 1 2 None 7 27 Infertility None 8 65 Scrotal pain, scrotal swelling 1 9 Bilateral epididymitis 9 25 Infertility None 10 4 mo Left scrotal swelling Contralateral (left) hydrocele Varicocele, scrotal pain None Varicocele, scrotal pain None Varicocele, scrotal pain 1 10 Ipsilateral epididymitis Scrotal pain None Varicocele None Scrotal pain 6 2 None Varicocele Contralateral varicocele Scrotal swelling Contralateral epididymal cyst Right scrotal swelling Right hydrocele, bilateral calculi Varicocele Ipsilateral varicocele, testicular microlithiasis Right scrotal swelling Contralateral hydrocele Scrotal pain 2 10 Contralateral varicocele Left scrotal swelling Left epididymal cyst, bilateral calculi *In cases of multiple calculi, the largest one was measured. Figure 4. In a 4-month-old infant, transverse sonography of both hemiscrotums shows 2 echogenic calculi (arrows) in the left hemiscrotum and hydrocele in the right hemiscrotum. F indicates fluid; LT, left; RT, right; and T, testis. trauma of the scrotal contents secondary to shocks and vibration of the saddle from the rough terrain. They found 127 scrotal calculi in 69 (81%) bikers. 5,7 Turgut et al 8 reported that scrotal calcifications were observed in 7% of equestrians. In our series, none of the patients had any memory of scrotal microtraumas related to prolonged cycling or riding, and our prevalence rate was 2.65%. The associated hydrocele is an exudate that accumulates between the membranes of the tunica. It usually consists of abundant clear serous fluid with a high protein concentration in most patients. 6,15 The presence of calculi and many particles in hydrocele suggests a disturbance mainly in salt reabsorption. However, the cholesterol content of the hydrocele is variable and may be high in chronic cases. The source of the cholesterol is thought to be obstruction of the lymphatic vessels of the tunica as a result of a low-grade infection. Namjoshi 6 reported that scrotal sonography revealed calculi and calcareous material in hydrocele in 32 of 350 patients, which corresponds to a prevalence rate of 9%. In our study, scrotal calculi were associated with hydrocele in 3 patients J Ultrasound Med 2007; 26:

5 Artas and Orhan Most scrotal calculi were less than 1 cm in diameter. In the study by Frauscher et al, 5 the scrotal calculi ranged from 0.2 to 1.4 cm in diameter, with a mean size of 0.4 ± 0.3 cm. In our series, we found scrotal calculi with a mean size of 4.22 ± 2.42 mm (range, 2 10 mm), similar to those reported in the medical literature. However, Li et al 16 reported a large stone measuring cm and weighing 420 g, which dropped down spontaneously from a 93-year-old man s scrotum. Parlaktas et al 17 reported multiple calculi in hydrocele along with findings from histopathologic examination of the excised tunica vaginalis testis and biochemical analysis of the calculi. Histologic examination of the tunica vaginalis testis revealed chronic inflammation with fibrosis. Biochemical analysis of the calculi, on the other hand, showed that they were composed of calcium, oxalate, and phosphorus. 17 In our series, 12 of the 23 patients had no pathologic abnormalities of the scrotal contents except for the scrotal calculi. In 12 patients with no pathologic abnormalities of the scrotum, the other hypothesis based on alterations in the scrotal fluid content may be more appropriate. Larger patient series with scrotal fluid and calculus analyses and histopathologic examination of the tunica vaginalis testis are necessary to understand the mechanism of calculus formation in such cases. In reviewing the medical literature, we were not able to find any case of scrotal calculi detected in infancy. Our series, however, included a case of scrotal calculi diagnosed in an infant (Figure 4). Although the exact etiology of scrotal calculi in infancy is not known, it could be assumed that hydrocele or deterioration of the scrotal fluid contents may lead to formation of calculi when the contralateral hydrocele is taken into account. However, detection of scrotal calculi in an infant poses new questions about the time required for the formation of a scrotal calculus. In conclusion, the prevalence of scrotal calculi in this series was 2.65%, and a minority of patients had other abnormalities, reflecting the generally benign etiology of these pearls. Although scrotal calculi are considered benign in nature, no follow-up findings have been reported in patients with scrotal calculi. To date, no information is available in the literature about the results of chronic irritation due to scrotal calculi. Further studies in larger series need to be performed to elucidate the formation mechanism and natural course of scrotal calculi, which usually are diagnosed incidentally during sonographic examinations and have been assumed to be benign entities. References 1. Kickham CT. Calcified hydrocele of the tunica vaginalis testis. N Engl J Med 1935; 212: Linkowski GD, Avellone A, Gooding GA. Scrotal calculi: sonographic detection. Radiology 1985; 156: Honore LH. Uncommon benign scrotal masses: a report of ten cases. Practitioner 1978; 221: Sánchez-Merino JM, Lancina Martín A, Grases Freixedas F, Parra Muntaner L, Gomez Cisneros SC, Garcia Alonso J. Intra-scrotal lithiasis: crystallographic analysis. Arch Esp Urol 2002; 55: Frauscher F, Klauser A, Stenzl A, Helweg G, Amort B, zur Nedden D. US findings in the scrotum of extreme mountain bikers. Radiology 2001; 219: Namjoshi SP. Calculi in hydroceles: sonographic diagnosis and significance. J Clin Ultrasound 1997; 25: Frauscher F, Klauser A, Hobisch A, Pallwein L, Stenzl A. Subclinical microtraumatisation of the scrotal contents in extreme mountain biking. Lancet 2000; 356: Turgut AT, Kosar U, Kosar P, Karabulut A. Scrotal sonographic findings in equestrians. J Ultrasound Med 2005; 24: Black JA, Patel A. Sonography of the abnormal extratesticular space. AJR Am J Roentgenol 1996; 167: Postma MP, Smith R. Scrotal cystocele with bladder calculi. AJR Am J Roentgenol 1986; 147: Patel VG, Singleton JM, Draycott TJ. Scrotal bladder with scrotal calculi. Br J Urol 1992; 69: Martin B, Tubiana JM. Significance of scrotal calcifications detected by sonography. J Clin Ultrasound 1988; 16: Bushby LH, Miller FN, Rosairo S, Clarke JL, Sidhu PS. Scrotal calcification: ultrasound appearances, distribution and etiology. Br J Radiol 2002; 75: Chatterjee AC. A rare complication of hydrocele. Br J Surg 1975; 61: Torok P, Perjes G, Rosdy E. Intrascrotal calcification. Int Urol Nephrol 1981; 13: Li GH, Li XD, Cheng S, Chen ZD. A large intrascrotal calculus. Asian J Androl 2005; 7: Parlaktas BS, Uluocak N, Filiz E, Erdemir F, Ozyurt H. Intrascrotal calculi: a very rare stone disease. Int J Urol 2006; 13: J Ultrasound Med 2007; 26: