Differential Diagnosis of Focal Epididymal Lesions With Gray Scale Sonographic, Color Doppler Sonographic, and Clinical Features

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1 Article Differential Diagnosis of Focal Epididymal Lesions With Gray Scale Sonographic, Color Doppler Sonographic, and Clinical Features Dal Mo Yang, MD, Sun Ho Kim, MD, Ha Na Kim, MD, Jee Hee Kang, MD, Tae Seok Seo, MD, Hee Young Hwang, MD, Hyung Sik Kim, MD, Hyuni Cho, MD Objective. To determine whether focal epididymal lesions can be differentiated on gray scale sonographic, color Doppler sonographic, and clinical features. Methods. This was a retrospective analysis of 60 focal epididymal lesions in 57 patients. Focal epididymal lesions were classified into 3 groups: nonspecific epididymitis (n = 43), tuberculous epididymitis (n = 10), and benign epididymal masses (n = 7). The following gray scale sonographic, color Doppler sonographic, and clinical features were analyzed: size, location, echogenicity, and heterogeneity of the lesion; hypoechoic or hyperechoic rim presence; hydrocele presence; degree of blood flow in the lesion; patient s age; duration of symptoms; and scrotal tenderness. Results. Lesions were larger in patients with tuberculous epididymitis than in those with either nonspecific epididymitis (P =.007) or benign epididymal masses (P =.0017). The hypoechoic or hyperechoic rim of the lesion was more common in patients with benign epididymal masses than in those with nonspecific epididymitis (P =.002). The degree of blood flow in the lesion was greater in patients with nonspecific epididymitis than in those with either tuberculous epididymitis (P =.0019) or benign epididymal masses (P <.001). The duration of symptoms was shorter in patients with nonspecific epididymitis than in those with either tuberculous epididymitis (P <.001) or benign epididymal masses (P =.0092). The frequency of scrotal tenderness was higher in patients with nonspecific epididymitis than in those with either tuberculous epididymitis (P <.001) or benign epididymal masses (P <.001). Conclusions. Gray scale sonographic, color Doppler sonographic, and some clinical features may be helpful for differential diagnosis of focal epididymal lesions. Key words: Doppler sonography; epididymal tumors; epididymis; epididymitis; sonography. Received August 12, 2002, from the Departments of Radiology (D.M.Y., S.H.K., H.N.K., J.H.K., T.S.S., H.Y.H., H.S.K.) and Pathology (H.C.), Gachon Medical School, Gil Medical Center, Incheon, South Korea. Revision requested October 1, Revised manuscript accepted for publication November 15, Address correspondence and reprint requests to Dal Mo Yang, MD, Department of Radiology, Gachon Medical School, Gil Medical Center, 1198 Guwol-Dong, Namdong-Gu, Incheon , South Korea. In the evaluation of scrotal disease, sonography is most commonly used and is accurate for distinguishing intratesticular from extratesticular lesions. 1 In addition, it is helpful for differential diagnosis of epididymal lesions. 2,3 The sonographic findings of nonspecific epididymitis are usually diffuse enlargement of the epididymis and uniform decreased echogenicity. 4 Tuberculous epididymitis may show diffusely enlarged heterogeneously hypoechoic lesions, diffusely enlarged homogeneously hypoechoic lesions, and nodular enlarged heterogeneously hypoechoic lesions on sonography. 2,5 7 In contrast, epididymal tumors appear as round or oval nodules with a homogeneous echo texture. 1,8 However, when the involvement of the epididymal 2003 by the American Institute of Ultrasound in Medicine J Ultrasound Med 22: , /03/$3.50

2 Differential Diagnosis of Focal Epididymal Lesions lesion has been localized, the differentiation between nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses such as benign epididymal tumors and sperm granulomas may be difficult. Makarainen et al 8 reported that the distinction between an epididymal adenomatoid tumor and focal enlargement of the epididymis due to chronic infection was not possible with sonography. Focal involvement of the epididymis occurs in 27% to 59% of tuberculous epididymitis cases 2,6 and in 20% to 30% of nonspecific epididymitis cases. 4 The differentiation of nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses is important because their treatment is markedly different. Nonspecific epididymitis usually responds to antibiotic therapy. 9 In tuberculous epididymitis, antituberculous chemotherapy is the initial course of action. 10 Benign epididymal tumors and sperm granulomas can be treated by local excision. 1,11 However, to our knowledge, the differentiation of focal epididymal lesions on sonography has not been described. The aim of our study was to determine whether various causes of focal epididymal lesions could be differentiated on gray scale sonographic, color Doppler sonographic, and clinical features. Materials and Methods Patients Scrotal sonographic reports, pathologic reports, and patient charts from May 1998 to August 2001 at our institution were searched to identify patients with proved nonspecific epididymitis, tuberculous epididymitis, and epididymal tumors. We identified 119 patients with pathologically or clinically proved nonspecific epididymitis and epididymo-orchitis, 12 patients with tuberculous epididymitis, and 6 patients with benign epididymal masses. Of these, we retrospectively reviewed the records of 57 patients with focal epididymal lesions who had histopathologically or clinically proved nonspecific epididymitis (n = 42), tuberculous epididymitis (n = 9), sperm granulomas (n = 4), an adenomatoid tumor (n = 1), and a leiomyoma (n = 1). The mean patient age was 41 years (range, years). Bilateral involvement of the epididymis was noted in 1 patient with nonspecific epididymitis, 1 with tuberculous epididymitis, and 1 with a leiomyoma. Therefore, the total numbers of cases were 43 with nonspecific epididymitis, 10 with tuberculous epididymitis, 4 with sperm granulomas, 1 with an adenomatoid tumor, and 2 with leiomyomas. All cases of tuberculous epididymitis were confirmed pathologically by epididymectomy (n = 4) or epididymo-orchiectomy (n = 6). All cases of sperm granuloma, leiomyoma, and adenomatoid tumor were confirmed pathologically by local excision. Nonspecific epididymitis cases were diagnosed on the basis of percutaneous needle aspiration (n = 2). The other 40 patients were conservatively treated with antibiotics and had clinical improvement within 23 days (range, days) of therapy. Sonographic Examination All sonographic examinations were performed with a 5- to 10-MHz linear array transducer (HDI 3000; Philips Medical Systems, Bothell, WA) or an 8- to 15-MHz linear array transducer (Sequoia; Acuson, a Siemens Company, Mountain View, CA). Color Doppler and power Doppler sonography were performed with optimized color Doppler parameters. The power level, threshold, persistence, and wall filter were individually adjusted to maximize the detection of blood flow through the field of view. Image Analysis Sonographic findings were determined by retrospective analysis of the images. We classified the epididymal lesions into 3 categories: nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses. The group of benign epididymal masses included sperm granulomas, the adenomatoid tumor, and leiomyomas. The numbers of cases totaled 43 for nonspecific epididymitis, 10 for tuberculous epididymitis, and 7 for benign epididymal masses. Malignant epididymal tumors were not found in our study. The gray scale and color Doppler sonographic images were interpreted by consensus of 2 radiologists, who determined the size, location, echogenicity, and heterogeneity of the epididymal lesion, the presence or absence of a hypoechoic or hyperechoic rim, the presence or absence of hydrocele, and the degree of blood flow in the lesion. Measurement of the lesion was performed with the width on a transverse scan or the anteroposterior diameter on a longitudinal scan. The location of the epididymal lesion was confirmed by gross pathologic findings in cases of tuberculous epididymitis and benign epididy- 136 J Ultrasound Med 22: , 2003

3 Yang et al mal masses and by sonographic findings in cases of nonspecific epididymitis. The location of the epididymal lesion was categorized as head, body, or tail. The grade of vascularity was classified according to a 4-point scale: 0 indicated no flow signals in the lesion; 1, a few spotty signals in the lesion; 2, flow signals in less than one third of the lesion; and 3, flow signals in more than one third of the lesion. Clinical Findings We reviewed the clinical charts of 57 patients and recorded each patient s age, duration of symptoms, and scrotal tenderness. The histopathologic findings in the tuberculous epididymitis, sperm granulomas, adenomatoid tumor, and leiomyomas were determined with review of the histopathologic reports. Statistical Analysis We performed statistical analysis to compare nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses using the Kruskal-Wallis test, Wilcoxon rank sum test, and Fisher exact test. P <.016 was considered statistically significant after Bonferroni adjustment for multiple comparisons. Odds ratios were calculated in terms of the presence of scrotal tenderness. All statistical analyses were performed with SAS software, release 6.12 (SAS Institute Inc, Cary, NC). Results Sonographic Findings The sonographic findings in patients with nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses are summarized in Table 1. The mean sizes of the lesions were 1.2 cm (range, cm) for nonspecific epididymitis (Fig. 1), 1.7 cm (range, cm), for tuberculous epididymitis (Fig. 2), and 0.8 cm (range, cm) for benign epididymal masses (Figs. 3 5). There were significant differences among the 3 groups in the mean sizes of the lesions on the basis of the Kruskal-Wallis test (P <.001). Lesions were significantly larger in patients with tuberculous epididymitis than in those with either nonspecific epididymitis (P =.007) or benign epididymal masses (P =.0017). In addition, lesions were significantly larger in patients with nonspecific epididymitis than in those with benign epididymal masses (P =.001). Peripheral hypoechoic or hyperechoic rims on the lesions were seen in 5 (12%) of 43 cases of nonspecific epididymitis (2 hypoechoic rims and 3 hyperechoic rims), 4 (40%) of 10 cases of tuberculous epididymitis (all hyperechoic rims), and 5 (71%) of 7 cases of benign epididymal masses (3 hypoechoic rims and 2 hyperechoic rims; Figs. 4 and 5). Hypoechoic or hyperechoic rims were found more frequently in patients with benign epididymal masses than in those with nonspecif- Table 1. Results of Gray Scale and Color Doppler Sonographic Findings of Focal Epididymal Lesions Lesions P Feature NSE (n = 43) TE (n = 10) BM (n = 7) NSE vs TE NSE vs BM TE vs BM Size, cm* 1.2 ± ± ± Location, n (%) Head 2 (5) 2 (20) 0 (0) NS NS NS Tail 41 (95) 8 (80) 7 (100) Echogenicity, n (%) Hypoechoic 38 (88) 10 (100) 4 (57) NS NS NS Isoechoic 5 (12) 0 (0) 3 (43) Heterogeneity, n (%) Present 14 (33) 6 (60) 2 (29) NS NS NS Absent 29 (67) 4 (40) 5 (71) Peripheral rim, n (%) Present 5 (12) 4 (40) 5 (71) NS.002 NS Absent 38 (88) 6 (60) 2 (29) Hydrocele, n (%) Present 21 (49) 3 (30) 0 (0) NS NS NS Absent 22 (51) 7 (70) 7 (100) Degree of blood flow* 2 ± ± ± <.001 NS BM indicates benign mass; NS, not significant; NSE, nonspecific epididymitis; and TE, tuberculous epididymitis. *Data are mean ± SD. J Ultrasound Med 22: ,

4 Differential Diagnosis of Focal Epididymal Lesions A B Figure 1. Images from a 23-year-old man with nonspecific epididymitis in the epididymal tail. A, Longitudinal gray scale sonogram showing a wellmarginated hypoechoic lesion, measuring about 1.2 cm in diameter, in the epididymal tail (arrows). B, Longitudinal color Doppler sonogram showing increased flow signals (grade 3 vascularity) in an epididymal lesion. Figure 2. Images from a 26-year-old man with tuberculous epididymitis in the epididymal tail. This longitudinal power Doppler sonogram shows a large heterogeneously hypoechoic lesion, measuring about 2.5 cm, with a few spotty flow signals (grade 1 vascularity) in the epididymal tail (arrows). ic epididymitis (P =.002), but there was no difference between tuberculous epididymitis and benign epididymal masses (P =.044) or between tuberculous epididymitis and nonspecific epididymitis (P =.574). There were significant differences among the 3 groups in the degree of blood flow in the lesions on the basis of the Kruskal-Wallis test (P <.001). The degree of blood flow was significantly greater in patients with nonspecific epididymitis than in those with either tuberculous epididymitis (P =.0019) or benign epididymal masses (P <.001; Figs. 1 5), but there was no significant difference between tuberculous epididymitis and benign epididymal masses (P =.0184). The tail of the epididymis was the most commonly involved location in nonspecific epididymitis (95%), tuberculous epididymitis (80%), and benign epididymal masses (100%). There were no significant differences in the location of the lesions between nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses (P.157). Two kinds of echogenicity of the lesion were observed: hypoechoic and isoechoic to the testis. Most cases of nonspecific epididymitis (88%), tuberculous epididymitis (100%), and benign epididymal masses (57%) were hypoechoic in terms of lesion echogenicity. Therefore, no statistically significant difference was noted with respect to lesion echogenicity (P.071). In terms of the heterogeneity of the lesion (P.151) and the presence or absence of hydrocele (P.017), there were no significant differences among the 3 groups. Clinical Findings The clinical findings in patients with nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses are summarized in Table 2. There were no significant differences in the ages of patients between patients with nonspecific epididymitis, tuberculous epididymitis, 138 J Ultrasound Med 22: , 2003

5 Yang et al and benign epididymal masses (P =.549, Kruskal- Wallis test; P.374, Wilcoxon rank sum test). Compared with the patients with nonspecific epididymitis, the patients with tuberculous epididymitis (P <.001) and those with benign epididymal masses (P =.0092) had longer durations of symptoms. However, there was no difference between tuberculous epididymitis and benign epididymal masses in the duration of symptoms (P =.377). There were significant differences among the 3 groups in the presence of scrotal tenderness on the basis of the Kruskal-Wallis test (P <.001). Scrotal tenderness was found more frequently in patients with nonspecific epididymitis than those with tuberculous epididymitis and benign epididymal masses (P <.001), but we found no significant difference between the latter 2 groups (P =.603). Discussion Figure 3. Image from a 48-year-old man with sperm granuloma in the epididymal tail. This longitudinal power Doppler sonogram shows a homogeneously hypoechoic lesion, measuring about 0.8 cm in diameter, with no flow signal (grade 0 vascularity) in the left epididymal tail (arrows). We observed that there are several differences between nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses on gray scale and color Doppler sonography: the size of the lesion, presence of a hypoechoic or hyperechoic rim, and degree of blood flow in the lesion. In terms of lesion size, tuberculous epididymitis is larger than nonspecific epididymitis or a benign epididymal mass. This result is related to the chronic course and minimal tenderness of tuberculous epididymitis. Consequently, patients with tuberculous epididymitis are usually admitted only after the formation of a large, indurated mass. 7 In contrast, nonspecific epididymitis is detected early because of its acute course and scrotal tenderness. 3,4 In benign masses of the epididymis, the mean measured size of 0.8 cm was the smallest of all focal epididymal lesion cases. These results differ from those of other authors, 1,8 who reported that mean sizes of benign epididymal lesions were 1.3 and 2.1 cm. The differences in results between these prior studies and our own may be explained by the small sample size of benign epididymal lesions in each individual study and may be related to the fact that the proportion of the epididymal masses was different in each. We observed a hypoechoic or hyperechoic rim in the peripheral portion of the lesion in 71% of benign epididymal masses, 40% of tuberculous epididymitis cases, and 12% of nonspecific epididymitis cases. Makarainen et al 8 found that an adenomatoid tumor in the epididymis may be surrounded by a hyperechoic rim, which represents epididymal tissue. In tuberculous epididymitis, a hyperechoic rim, representing an abscess wall, may be seen. 7 Interestingly, in our Figure 4. Image from a 49-year-old man with an adenomatoid tumor in the epididymal tail. This transverse power Doppler sonogram shows a small hypoechoic lesion with a hyperechoic rim (arrows), measuring about 0.6 cm, and a spotty flow signal (grade 1 vascularity) in the epididymal tail. J Ultrasound Med 22: ,

6 Differential Diagnosis of Focal Epididymal Lesions Figure 5. Image from a 38-year-old man with a leiomyoma in the epididymal tail. This transverse power Doppler sonogram shows a round isoechoic lesion with a hypoechoic rim, measuring about 0.8 cm, and a few spotty flow signals (grade 1 vascularity) in the epididymal tail (arrows). study 2 patients with nonspecific epididymitis and 3 patients with benign epididymal masses (2 sperm granulomas and 1 leiomyoma) had hypoechoic rims of the peripheral portions of the lesions. We think that the hypoechoic rim may correspond to compressed epididymal parenchyma. Color Doppler sonography provides simultaneous display of tissue morphologic characteristics in gray scale and blood flow in the lesion. It helps in the diagnosis of acute inflammatory disease 4 and in differentiating between tuberculous and pyogenic abscesses. 3 We observed that it also helps in the differential diagnosis of focal epididymal lesions because the degree of blood flow is greater in patients with nonspecific epididymitis than in those with tuberculous epididymitis or benign epididymal masses. Nonspecific epididymitis usually has an increased number and concentration of identifiable vessels in the affected region of the epididymis on color Doppler sonography. 4 In our study, there was no blood flow and a minimal number of vessels within the lesions in patients with tuberculous epididymitis and benign epididymal masses such as sperm granuloma, adenomatoid tumors, and leiomyomas of the epididymis. This finding is in accordance with those of other authors, 7,12 who reported that tuberculous epididymitis and benign epididymal masses showed no increased flow on color Doppler sonography. The characteristic sonographic finding in tuberculous epididymitis was heterogeneous echogenicity of the lesion. 2 This finding is related to caseation necrosis, granuloma, and fibrosis of the lesion. In contrast, the sonographic findings of nonspecific epididymitis and benign epididymal masses were usually homogeneous in echogenicity. 1,4,8 However, in our study, there was no difference in terms of heterogeneity of the epididymal lesions between nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses. We observed heterogeneity of the epididymal lesions in 60% of cases of tuberculous epididymitis, 33% of cases of nonspecific epididymitis, and 29% of cases of benign epididymal masses. We observed that most of the focal epididymal lesions were hypoechoic and located at the tail of the epididymis. Thus, the echogenicity and location of the lesion are not useful in differentiating between nonspecific epididymitis, tuberculous Table 2. Results of Clinical Findings of Focal Epididymal Lesions Lesions P Feature NSE (n = 43) TE (n = 10) BM (n = 7) NSE vs TE NSE vs BM TE vs BM Age, y* 40 ± ± ± 9 NS NS NS Duration of symptoms, d* 8 ± ± ± 1132 < Tenderness of scrotum, n (%) Present 39 (91) 3 (30) 1 (14) <.001 < Absent 4 (9) 7 (70) 6 (86) BM indicates benign mass; NS, not significant; NSE, nonspecific epididymitis; and TE, tuberculous epididymitis. *Data are mean ± SD. Odds ratio and 95% confidence interval, 2.55 ( ). Odds ratio and 95% confidence interval, 2.44 ( ). Odds ratio and 95% confidence interval, 1.39 ( ). 140 J Ultrasound Med 22: , 2003

7 Yang et al epididymitis, and benign epididymal masses. In addition, no differences were noted in terms of the presence or absence of hydrocele among the 3 groups. In our study, there were some differences between nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses in clinical features: short duration of symptoms and the presence of scrotal tenderness in patients with nonspecific epididymitis compared with those with tuberculous epididymitis or benign epididymal masses. These differences are related to the differing courses of the diseases. Nonspecific epididymitis is an acute inflammatory condition. 4 In contrast, tuberculous epididymitis is usually a chronic disease, and scrotal tenderness is usually absent, 2,3 whereas benign epididymal masses are not tender and are usually discovered incidentally. 8,11,12 Therefore, when the differentiation between nonspecific epididymitis, tuberculous epididymitis, and benign epididymal masses is difficult on sonography, the clinical features, including the duration of symptoms and the presence or absence of scrotal tenderness, may be helpful in some instances. A number of limitations in this study should be considered. First, this study consisted of retrospective interpretation of sonographic images. We may have missed the presence of a peripheral rim in some cases, because the images were not created with such a finding in mind. Therefore, our frequency data for the presence of a peripheral rim may be understated. In addition, the retrospective application of criteria to grade the vascularity of lesions may be problematic. Second, the study featured a small sample size, particularly the number of patients with benign epididymal masses. Thus, further study will be necessary to more fully examine the differentiation between focal epididymitis and benign epididymal masses. Third, most nonspecific epididymitis cases were not pathologically confirmed. We think that these cases were nonspecific epididymitis because of their clinical improvement after antibiotic treatment. In summary, most of the focal epididymal lesions in our study were hypoechoic and located at the tail portion of the epididymis. Lesions were largest in patients with tuberculous epididymitis and smallest in patients with benign epididymal masses. Hypoechoic or hyperechoic rims of the lesions were most common in patients with benign epididymal masses. The degree of blood flow was greater in patients with nonspecific epididymitis than in those with either tuberculous epididymitis or benign epididymal masses. In clinical features, the patients with nonspecific epididymitis had a shorter duration of symptoms and a higher frequency of scrotal tenderness than those with either tuberculous epididymitis or benign epididymal masses. In conclusion, for the differentiation of focal epididymal lesions, the following characteristics of gray scale sonographic, color Doppler sonographic, and some clinical features may be helpful. A great degree of blood flow in the lesion, a short duration of symptoms, and the presence of scrotal tenderness are indicative of nonspecific epididymitis. Conversely, tuberculous epididymitis and benign epididymal masses have a lesser degree of blood flow in the lesion, a long duration of symptoms, and the absence of scrotal tenderness. For differentiation between tuberculous epididymitis and benign epididymal masses, the size and heterogeneity of the epididymal lesion, along with the presence or absence of a hypoechoic rim, may be helpful. References 1. Frates MC, Benson CB, DiSalvo DN, Brown DL, Laing FC, Doubilet PM. Solid extratesticular masses evaluated with sonography: pathologic correlation. Radiology 1997; 204: Kim SH, Pollack HM, Cho KS, Pollack MS, Han MC. Tuberculous epididymitis and epididymo-orchitis: sonographic findings. J Urol 1993; 150: Yang DM, Yoon MH, Kim HS, et al. Comparison of tuberculous and pyogenic epididymal abscesses: clinical, gray-scale sonographic, and color Doppler sonographic features. AJR Am J Roentgenol 2001; 177: Horstman WG, Middleton WD, Melson GL. Scrotal inflammatory disease: color Doppler US findings. Radiology 1991; 179: Muttarak M, Peh WCG, Lojanapiwat B, Chaiwun B. Tuberculous epididymitis and epididymo-orchitis: sonographic appearances. AJR Am J Roentgenol 2001; 176: Chung JJ, Kim MJ, Lee T, Yoo HS, Lee JT. Sonographic findings in tuberculous epididymitis and epididymoorchitis. J Clin Ultrasound 1997; 25: J Ultrasound Med 22: ,

8 Differential Diagnosis of Focal Epididymal Lesions 7. Yang DM, Chang MS, Oh YH, Yoon MH, Kim HS, Chung JW. Chronic tuberculous epididymitis: color Doppler US findings with histopathologic correlation. Abdom Imaging 2000; 25: Makarainen HP, Tammela TLJ, Karttunen TJ, Mattila SI, Hellstrom PA, Kontturi MJ. Intrascrotal adenomatoid tumors and their ultrasound findings. J Clin Ultrasound 1993; 21: Goldstein M. Surgical management of male infertility and other scrotal disorders. In: Walsh PC, Retik AB, Vaughan DE, Wein AJ (eds). Campbell s Urology. Philadelphia, PA: WB Saunders Co; 1998: Gow JG. Genitourinary tuberculosis. In: Walsh PC, Retik AB, Vaughan DE, Wein AJ (eds). Campbell s Urology. Philadelphia, PA: WB Saunders Co; 1998: Ramanathan K, Yaghoobian J, Pinck RL. Sperm granuloma. J Clin Ultrasound 1986; 14: Black JAR, Patel A. Sonography of the abnormal extratesticular space. AJR Am J Roentgenol 1996; 167: J Ultrasound Med 22: , 2003