Radionucide Imaging of Sequential Torsions of the Appendix Testis

Alan J. Fischman, Edwin L. Palmer, and James A. Scott Department ofRadiology, Massachusetts General Hospital, Boston, Massachusetts

Radionuclide imaging is the diagnostic procedure of choice for evaluation of acute disorders of the scrotum, permitting rapid differentiation of torsion of the spermatic cord from inflammatoryprocesses.Themethodis lesssuccessfulin diagnosingtorsionof the testicular appendages.Inthe majorityof reportedcasesof torsionof the appendixtestisthe scan appearsnormal.Ina verylimitednumberof casesincreasedperfusionto the affectedside hasbeennoted.Wereporta caseof metachronoustorsionof boththe appendicestestis.In eachinstance,therewasdecreasedtraceruptakeon the affectedside,suggestiveof early torsionof the testicle.Thesequentialinvolvementof eachtestiswith a ninemonthinterval betweenrespectivetorsionsprovidesa uniqueexamplewhereeachtestis serves, sequentially,as a normalcontrolfor the torsedcontralateralappendage.

J NuclMed 28:119—121,1987

dionuclide imaging of the scrotum with techne radionuclide testicular scan was requested. Using a small field tium-99m (99mTc)sodium pertechnetate was first intro of-view gamma camera equipped with a high resolution par duced by Nadel et al. in 1973 (1). The primary goal of allel hole collimator, the child was placed supine beneath the this procedure in the evaluation of the acute scrotum is camera with the penile-scrotal junction in the center of the to accurately direct patients with torsion to early sur field and the penis taped back over the pubis. Following the gical exploration, thus increasing the likelihood of a i.v. bolus injection of 10 mCi (370 MBq) of @mTc sodium pertechnetate, a radioangiogram was obtained at a rate of two salvageable testicle and avoiding unnecessary surgery in seconds per frame. This was followed by static images using patients with inflammatory disease. While the scan both parallel hole and pinhole collimation. Images were oh appearance of all phases of testicular torsion have been tamed both with and without shielding of thigh activity and well characterized (2—4),there have been a very limited with and without a cobalt-57 marker of the scrotal raphe. All number of reports describing the scintigraphic evalua static images were accumulated for 1,000 k. tion of the testicular appendages. We report a case of The radioangiogram revealed a symmetric appearance of recurrent torsion of the appendix testis in a 9-yr-old the scrotum. Static images demonstrated an asymmetry of child. tracer distribution, with decreased activity on the right com pared with the left hemiscrotum (Fig. 1). While a focal area of photopenia could not be localized to the right testicle, the CASE REPORT possibility of torsion was strongly suspected on clinical grounds, and it was elected to perform a surgical exploration A 9-yr-old child presented with a 10-hr history of right ofthe scrotum. scrotal pain and fever to 101°F.Past medical history was At surgery the testicle, epididymis, and spermatic cord noncontributory. The patient denied a history of previous structures appeared completely normal. The appendix testis, similar pain, abdominal pain, trauma, dysuria or hematuria. however, was gangrenous in appearance, and was swollen and On physical examination, the patient had prepubertal genitalia erythematous. Pathological examination revealed the appen with bilaterally descended testicles. No erythema over the dix testis to be inflamed and edematous with fibrous infiltra scrotum was noted. The right testicle was very painful to tion. There was no evidence of hydrocele at surgery. palpation but no mass lesion was detected. The spermatic The patient's postoperative course was uneventful, and he cord was unremarkable. Urine analysis was within normal was well until 9 mo later, at which time he experienced the limits and there was no subsequent growth on urine culture. acute onset ofleft scrotal pain, which was described as “sharp, To exclude the diagnosis oftesticular torsion, an emergency knife-like―and worse than the previous episode involving the right side. The history, physical examination, and laboratory ReceivedMay 22, 1986:revisionaccepted Aug. 1, 1986. tests were nearly identical to the previous contralateral epi For reprints contact: James A. Scott, Dept. of Radiology, sode. MassachusettsGeneral Hospital, Boston, MA 02114. The diagnosis of testicular torsion was again considered,

Volume28 •Number1 •January1987 119 perfusion to the testicles. Static images demonstrated mini mally decreased activity in the left hemiscrotum as compared to the right (Fig. 2), representing nearly a mirror image ap pearance when compared with the initial episode. The patient was again explored surgically, with nearly identical operative and pathological observations, this time involving the left appendix testis. Again, a hydrocele was not present at surgery.

DISCUSSION

Since the first report of torsion of a testicular appen dage by Colt in 1922 (5), more than 400 cases have been reported. The vast majority of these torsions oc cured in patients between the ages of 10 and 13 yr (6), with only six cases reported in patients more than 18 yr old (7). There are four testicular appendages: (a) the appendix testis, (b) the appendix epididymis, (c) the paradidymis, and (d) the vas aberrans ( 7). Torsion of any of these FIGURE 1 structures may occur. Involvement of the appendix Technetium-99msodium pertechnetatetesticular scan. testis and the appendix epididymis represent the major Static images show an area of decreased tracer accumu ity of cases, however, with the appendix testis account lationinthe righthemiscrotum(arrow). ing for >90% of the total (2). Clinically the patient usually presents with moderate pain in the scrotum, and a testicular scan performed. The procedure for performing testis, groin, or lower abdomen which may often be the scan was identical to the previous study with the exception attributed to minimal trauma (8). Tenderness is usually that a converging collimator was used to accumulate some of more focal than in testicular torsion and is often local the static images. The radioangiogram revealed symmetric ized to the upper pole of the testicle. Physical exami nation may reveal point tenderness localized to a pea sized structure in the vicinity of the upper pole of the testicle. Sometimes a blue discoloration can be seen through the skin overlying the twisted appendage. Al though secondary hydrocele formation is common, more serious complications only rarely follow an un treated case of torsion of the appendix testis. Atrophy ofthe appendage and resolution ofthe symptoms is the most common outcome; however, torsion may be re current. One case of torsion of the appendix testis leading to torsion of the testis has been reported (9). To date there have been less than 20 reports describ ing the radionuclide scan appearance of torsion of testicular appendages. Most authors have reported nor mal perfusion and static images (10—13).Others have reported slightly increased perfusion (14,15), possibly due to reactive hyperemia. Two cases presenting with generally increased activity as well as a photopenic zone that was too small to represent an entire testis have also been reported (16). Recently Chen et al. reported a case of torsion of the appendix testis in which the radio FIGURE 2 nuclide scan showed a poorly perfused testicle (4). This Technetium-99msodium pertechnetatetesticular scan. observation is similar to the scan appearance reported Static images show an area of decreased tracer accumu here. Since this pattern is extremely difficult to distin lation in the left hemiscrotum (arrow). Identical pattern to guish from early testicular torsion, surgical exploration Figure1, exceptfor right-leftinversionof the photopenic focus. The linear actiVity distribution in the scrotal midline is nearly unavoidable. andextendingabovethe bladderis a cobalt-57markerof In conclusion, torsion of the appendix testis can the scrotalraphe. produce a variable pattern on radionuclide scan, with

120 Fischman,Palmer,andScott TheJournalof NuclearMedicine the affected testis showing increased, decreased, or nor testicular appendages, presentation of 43 new cases mal radionuclide accumulation relative to the normal and a collective review. J Urol 1970; 104:598—600. 7. Altaffer LF, Steele SM. Torsion of testicular appen testis. Only those cases with decreased uptake, as in the dages in men. J Urol 1980; 124:56—57. case reported here are likely to require surgical explo 8. Fitzpatrick Ri. Torsion of the appendix testis. J Urol ration. The sequential involvement of each testicle in 1958; 79:52 1—526. this case provides a unique example in which each testis 9. Lambert J, Smith RE. Torsion of the testicle and of serves as a normal control for the torsed contralateral the hydatid ofMorgagni. BrJSurg 1938; 25:553—560. 10. Datta NS, Mishkin ES. Radionuclide imaging in in appendage. trascrotallesions.JAMA 1975;231:1060—1062. 11. Holder LE, Martire JR, Holmes ER, et al. Testicular REFERENCES radionuclide angiography and static imaging: anat omy, scintigraphic interpretation and clinical indica 1. Nadel NS, Gitter MH, Hahn LC, et al. Pre-operative tions. Radiology 1977; 125:739—752. diagnosis of testicular torsion. Urology 1973; 1:478— 12. Hitch DC, Gilday DL, Shandling B, et al. A new 479. approach to the diagnosis of testicular torsion. J Pe 2. Holder LE, Melloul M, Chen D. Current status of diatrSurg1976;11:537—541. radionuclide scrotal imaging. Semin Nucl Med 1981; 13. Mishkin ES. Differential diagnostic features of the 9:232—248. radionuclide scrotal image. Am J Roentgenol 1977; 3. Chen DCP, Holder LE, Melloul M. Radionuclide 128:127—129. scrotal imaging. Further experience with 210 patients. 14. Smith SP, King LR. Torsion of the testis: techniques Part 1: anatomy, physiology and methods. J Nucl Med ofassessment.UrolClinNorthAm 1979;6:429—443. 1983; 24:735—742. 15. Kogan SJ, Lutzker LG, Perez LA, et al. The value of 4. Chen DCP, Holder LE, Melloul M. Radionuclide the negative radionuclide scrotal scan in the manage scrotal imaging with 210 patients. Part 2: results and ment of the acutely inflamed scrotum in children. J discussion.JNuclMed 1983;24:841—853. Urol1979;122:223—225. 5. Colt GH. Torsion of the hydatid of Morgagni. Br J 16. Lutzker LG, Novick I, Perez LA, et al. Radionuclide Surg 1922; 9:464—465. scrotal imaging. Appl Radiol Nucl Med 1977; 6:187— 6. SkoglundRW, McRobertsJW, RagdeH. Torsion of 195.

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