Splenogonadal Fusion: An Unusual Case of an Acute Scrotum

Case Review Splenogonadal Fusion: An Unusual Case of an Acute Scrotum Rena D. Malik, MD, Dennis B. Liu, MD, FAAP, FACS The University of Chicago Medicine & Biological Sciences, Chicago, IL We highlight a case on a normal left testicle with a fibrovascular cord with three nodules consistent with splenic tissue. The torsed splenule demonstrated hemorrhage with neutrophilic infiltrate and thrombus consistent with chronic infarction and torsion. Splenogonadal fusion (SGF) is a rather rare entity, with approximately 184 cases reported in the literature. The most comprehensive review was that of 123 cases completed by Carragher in 1990. Since then, an additional 61 cases have been reported in the scientific literature. We have studied these 61 cases in detail and have included a summary of that information here. [ Rev Urol. 2013;15(4):197-201 doi: 10.3909/riu0593] ® © 2014 MedReviews , LLC Key words Splenogonadal fusion • Acute scrotum A 10-year-old boy presented with worsening left-sided scrotal pain of 12 hours’ duration. The patient reported similar previous episodes occurring intermittently over the past several months. His past medical history was significant for left hip dysplasia, requiring multiple hip surgeries. On examination, he was found to have an edematous left hemiscrotum with a left testicle that was rigid, tender, and noted to be in a transverse lie. The ultrasound revealed possible polyorchism, with two testicles on the left and one on the right (Figure 1), and left epididymitis. One of the left testicles demonstrated a loss of blood flow consistent with testicular torsion (Figure 2). The patient was taken to the operating room for immediate scrotal exploration. A normalappearing left testicle with a normal epididymis was noted. However, two accessory structures were noted, one of which was torsed 720° (Figure 3). An inguinal incision was then made and a third Vol. 15 No. 4 • 2013 • Reviews in Urology • 197 4004170006_RIU0593.indd 197 16/01/14 5:27 PM Splenogonadal Fusion continued Discussion Splenogonadal fusion (SGF) is a rather rare entity with approximately 184 cases reported in the literature. The most comprehensive case review was that of 123 cases completed by Carragher in 1990.1 Since then, an additional 61 cases have been reported in the scientific literature. We have reviewed these cases in detail and included the summarized data herein. Figure 2. Doppler ultrasound of left hemiscrotum. No evidence of blood flow to left spherical structure. Etiology SGF is thought to occur between the fifth and eighth week of gestation, at which time the splenic anlage is within close proximity to the left urogenital fold until gonadal descent begins at the eighth week.1 Active development of the limb bud and mandible also occur during this time, which explain the occurrence of coexisting limb anomalies and micrognathia.2 Three major theories have been proposed. Sneath suggested that inflammation between the gonadal ridge and spleen results in an adhesion between the two.3 However, this theory does not explain the incidence of right-sided SGF or intraovarian or splenic tissue localized beneath the tunica albuginiea.4,5 von Hochstetter postulated a retroperitoneal pathway that allows communication between the splenic and gonadal tissue.5 Conversely, Putschar and Manion believed that SGF could be explained by the envelopment of splenic tissue by the tunica albuginea of the gonad.6 accessory structure was noted. All three structures were connected with fibrous tissue, giving a “rosary bead” appearance. The left accessory structures were removed, a left testicular biopsy was taken, and bilateral scrotal orchipexies were performed. Classification SGF is classified into two distinct forms. A continuous variant is characterized when there is a discrete connection between the anatomic spleen and gonad by a fibrous cord. This may occasionally be accompanied by beads of Figure 1. Ultrasound of the left hemiscrotum reveals two spherical structures; the one on the left is heterogeneous and hyperdense in comparison to the right. Pathology revealed a normal left testicle with a fibrovascular cord with three nodules consistent with splenic tissue. The torsed splenule demonstrated hemorrhage with neutrophillic infiltrate and thrombus consistent with chronic infarction and torsion (Figure 4). 198 • Vol. 15 No. 4 • 2013 • Reviews in Urology 4004170006_RIU0593.indd 198 16/01/14 5:27 PM Splenogonadal Fusion Table 1 Age at Diagnosis N (%) 0-9 0-19 20-29 30-39 40-49 50-59 60-89 Unknown 85 (46) 40 (22) 30 (16) 4 (2) 7 (4) 4 (2) 4 (2) 2 (1) is likely due to underrepresentation in females based on the location of the gonad. In females, presentation of SGF occurs as incidental findings on autopsy or at laparotomy for unrelated conditions. Approximately 97% of reported cases were associated with the left gonad. The most common clinical presentations in males are scrotal swelling, inguinal hernias, and exploration for cryptorchidism (Table 2). Our case is unique in that it is one of the few cases that presented as an acute scrotum thought to be a testicular torsion. Figure 3. Torsed accessory spleen with splenogonadal fusion. Figure 4. Splenogonadal fusion, continuous type with three accessory structures. splenic tissue along the cord, as is the case presented here.1 The discontinuous form, however, reveals no continuity with the anatomic spleen similar to an accessory spleen.7 The continuous form has a slightly higher prevalence of approximately 58%, as documented in the published literature. Age (y) Presentation SGF has been reported in both males and females and in a wide range of age groups. Most commonly, it is seen in male patients under age 39 years and localized to the left side (Table 1). The male:female ratio for SGF is 14.3:1, with 93% of cases being reported in male patients; however, this Associations SGF has been reported to have multiple associations with major congenital abnormalities. The majority of anomalies are seen in patients with continuous SGF, with a fivefold increase in occurrence in comparison with patients with discontinuous SGF.12 Commonly reported anomalies include limb defects and craniofacial abnormalities, specifically micrognathia. Of a total of 184 cases in the literature, 26% were noted to have an association with one or more congenital abnormalities (Table 3). In addition, an association with cryptorchidism was frequently noted. In our review of the 61 cases, approximately 36% were found to Vol. 15 No. 4 • 2013 • Reviews in Urology • 199 4004170006_RIU0593.indd 199 16/01/14 5:27 PM Splenogonadal Fusion continued homogenous extra-testicular mass that is usually hypoechoic or isoechoic to the adjacent testicle.26 Table 2 Presentation Clinical Presentation Scrotal swelling Autopsy Left undescended testes Left inguinal hernia Acute abdomen Scrotal exploration: torsion Other* Inguinal mass LIH & UDT N (%) 78 (42) 33 (18) 31 (17) 26 (14) 5 (3) 5 (3) 3 (2) 2(1) 1 (1) *Infertility, L atrophic testes, chronic constipation/abdominal pain, incidentally found. LIH, left inguinal hernia; UDT, undescended testicles. Data from Keyik B et al,8 Steinmetz AP et al,9 Patafio FM et al,10 and Imperial and Sidhu.11 Table 3 Congenital Anomalies Associated With Splenogonadal Fusion Congenital Anomaly N Any associated anomaly Limb defects Micrognathia 47 36 17 have cryptorchidism either on the ipsilateral or contralatral testicle. Other noted congenital anomalies reported included cleft palate, moebius syndrome, hypospadias, Roberts-SC phocomelia syndrome, coarctation of the aorta, osteogenesis imperfecta, persistent mullerian duct syndrome, Potter syndrome, gastrointestinal malrotation, anal stenosis, and transverse testicular ectopia.13-19 Three cases of malignancy have been reported11,20,21; two were preoperatively thought to be bilateral cyptorchidism, and the other was a testicular mass in a testicle that had previously undergone orchiopexy. Postoperatively, the patients were found to have nonseminomatous germ cell tumor, anaplastic seminoma, and mixed malignant germ cell tumor, respectively. This, however, has been speculated to be correlated with cryptorchidism rather than the occurrence of SGF.12 Diagnosis Rarely is a diagnosis of SGF found preoperatively; usually it is in instances in which SGF has been encountered previously. Diagnostic tests that have been used include technicium-99m sulfur colloid scan, ultrasound, and contrastenhanced spiral computed tomography.2,22-25 Technicium-99m sulfur colloid liver-spleen scan detects accessory splenic tissue and can help identify SGF when a strong preoperative suspicion exists. Ultrasound has been demonstrated to assist in the diagnosis when a cord connecting the spleen to the testicle is visualized. Commonly, the splenic tissue is visualized on ultrasound as a well-encapsulated, Histology In the large majority of cases in which histology is discussed, the splenic tissue seen in SGF is similar in appearance to normal splenic tissue with some potentially minor abnormalities such as increasing lobulation, fissuring, fibrosis, thrombosis, calcification, fat degradation, or hemispheric deposits.1 One case has been reported with intermingling of splenic and gonadal tissue histologically.27 Treatment Given the rarity and unfamiliarity of SGF, surgeons often perform unnecessary orchiectomies. Based on our review of the 61 reported cases occurring since 1990, 24% underwent an orchiectomy due to a dysplastic or atrophic gonad, or the surgeon reported an inability to separate the splenic mass completely. Previously, Carragher reported 37% of the 123 cases reviewed had undergone orchiectomy.1 However, complete excision of the splenic tissue is sufficient, and preservation of the testes, specifically in this young population, is optimal. References 1. 2. 3. 4. 5. 6. 7. 8. Carragher AM. One hundred years of splenogonadal fusion. Urology. 1990;35:471-475. Varma DR, Sirineni GR, Rao MV, et al. Sonographic and CT features of splenogonadal fusion. Pediatr Radiol. 2007;37:916-919. Sneath WA. An apparent third testicle consisting of a scrotal spleen. J Anat Physiol.1913;47(Pt 3):340-342. Gouw AS, Elema JD, Bink-Boelkens MT, et al. The spectrum of splenogonadal fusion. Case report and review of 84 reported cases. Eur J Pediatr. 1985;144:316-323. von Hochstetter A. Milzgewebe im linken Ovarium des linken Individualteiles eines menschlichen Thoracopagus. Virchows Arch. 1953;324:36-54. Putschar WG, Manion WC. Splenicgonadal fusion. Am J Pathol. 1956;32:15-33. Duncan WL Jr, Barraza MA. Splenogonadal fusion: a case report and review of literature. J Pediatr Surg. 2005;40:e5-e7. Keyik B, Yanik B, Conkbayir I, et al. Continuous-type splenogonadal fusion associated with an ipsilateral testicular atrophy: sonographic findings. J Clin Ultrasound. 2010;38:161-163. 200 • Vol. 15 No. 4 • 2013 • Reviews in Urology 4004170006_RIU0593.indd 200 16/01/14 5:27 PM Splenogonadal Fusion 9. 10. 11. 12. 13. 14. Steinmetz AP, Rappoport A, Nikolov G, et al. Splenogonadal fusion diagnosed by spleen scintigraphy. J Nucl Med. 1997;38:1153-1155. Patafio FM, Dufton JA, Walker DR. Case of the month #173: splenogonadal fusion. Can Assoc Radiol J. 2011;62:302-304. Imperial SL, Sidhu JS. Nonseminomatous germ cell tumor arising in splenogonadal fusion. Arch Pathol Lab Med. 2002;126:1222-1225. Khairat AB, Ismail AM. Splenogonadal fusion: case presentation and literature review. J Pediatric Surg.2005;40:1357-1360. Buccoliero AM, Messineo A, Castiglione F, et al. Splenogonadal fusion: exceptional association with Moebius syndrome and intestinal intussusception. Fetal Pediatr Pathol. 2011;30:220-224. Balaji KC, Caldamone AA, Rabinowitz R, et al. Splenogonadal fusion. J Urol. 1996;156(2 Pt 2): 854-856. 15. 16. 17. 18. 19. 20. Takemoto J, Takeyama J, Sakai K. Perisplenic splenogonadal fusion. Int J Urol. 2009;16:647. de Ravel TJ, Seftel MD, Wright CA. Tetra-amelia and splenogonadal fusion in Roberts syndrome. Am J Med Genet. 1997;68:185-189. Kameoka H, Yamada R, Sonoda T, Okuyama A. Splenic gonadal fusion with persistent Müllerian Duct Syndrome. Urol Int. 1993;50:170-173. McPherson F, Frias JL, Spicer D, et al. Splenogonadal fusion-limb defect “syndrome” and associated malformations. Am J Med Genet A. 2003;120A:518-522. Basbug M, Akgun H, Ozgun MT, et al. Prenatal sonographic findings in a fetus with splenogonadal fusion limb defect syndrome. J Clin Ultrasound. 2009;37: 298-301. Thomsen BM, Wierød FS, Rasmussen KC. Combined malignant testicular tumor and splenogonadal fusion. A case story. Scand J Urol Nephrol. 1997;31:393-395. 21. 22. 23. 24. 25. 26. 27. Falkowski WS, Carter MF. Splenogonadal fusion associated with an anaplastic seminoma. J Urol. 1980;124:562-564. Patel RV. Splenogonadal fusion. J. Pediatr Surg. 1995;30:873-874. Guarin U, Dimitrieva Z, Ashley SJ. Splenogonadal fusion—a rare congenital anomaly demonstrated by 99Tc-sulfur colloid imaging: case report. J Nucl Med.1975;16:922-924. Sloan JP, Kapila L, Wastie M. Technetium liver scan in the diagnosis of splenic-gonadal fusion. Br J Urol. 1987;59:360-361. Aslan P, Burn J, Farrell C. Spleno-gonadal fusion of the testis. Aust N Z J Surg. 1997;67:899-900. Cirillo RL Jr, Coley BD, Binkovitz LA, Jayanthi RV. Sonographic findings in splenogonadal fusion. Pediatr Radiol.1999;29:73-75. Bennett-Jones MJ, Hill CA. Accessory spleen in the scrotum. Br J Surg. 1952;40:259-262. Main PoinTs • Splenogonadal fusion (SGF) is classified into two distinct forms: (1) continuous, which is characterized when there is a discrete connection between the anatomic spleen and gonad by a fibrous cord; and (2) discontinuous, which reveals no continuity with the anatomic spleen similar to an accessory spleen. The continuous form has a slightly higher prevalence in the published literature of approximately 58%. • SGF has been reported in males and females and in a wide range of age groups. Most commonly, it is seen in male patients under age 39 years and is localized to the left side. • Commonly reported anomalies include limb defects and craniofacial abnormalities, specifically micrognathia. Of a total of 184 cases in the literature, 26% were noted to have an association with one or more congenital abnormalities. • Given the rarity and unfamiliarity of SGF, surgeons often perform unnecessary orchiectomies. However, complete excision of the splenic tissue is sufficient, and preservation of the testes, specifically in this young population, is optimal. Vol. 15 No. 4 • 2013 • Reviews in Urology • 201 4004170006_RIU0593.indd 201 16/01/14 5:27 PM