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The differential diagnosis of acute scrotal pain includes testicular torsion, torsion of the testicular appendages, epididymitis, incarcerated hernia, and trauma, among others. Frequent causes of acute scrotal pain include testicular torsion or epididymitis in adults, with the added possibility of appendage torsion in children (Table 93-1). Because of the potential for infarction and infertility, testicular torsion must be the primary consideration in acute scrotal pain. The annual incidence of testicular torsion is 3.8 in 100,00 males under the age of 18.29 Testicular torsion presents in a bimodal age distribution, with extravaginal torsion occurring in the perinatal period and intravaginal torsion peaking during puberty,29 although this may occur at any age.
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Torsion of the testis or spermatic cord results from abnormal fixation of the testis within the tunica vaginalis. This allows the testis to twist, especially after episodes of minor trauma and during periods of testicular growth such as puberty. Torsion usually occurs in the absence of a preceding event; only a small percentage occurs due to associated trauma. Torsion may occur during sleep, when unilateral cremasteric muscle contraction results in twisting of the testis. Inadequate fixation of the tunica vaginalis to the posterior scrotal wall (bell-clapper deformity) places the testis at risk for torsion. A testis aligned along a horizontal rather than a vertical axis is at particular risk.
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Patients usually complain of acute severe pain, usually felt in the lower abdominal quadrant, the inguinal canal, or the testis. Although the pain may be constant or intermittent, it is not positional in nature, because testicular torsion is primarily an ischemic event that becomes inflammatory only after the testis has infarcted. The presence of vomiting makes the diagnosis of testicular torsion more likely.30
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When examined early, the involved testis is firm, tender, and often higher than the contralateral testis and frequently with a transverse lie.31 The epididymis may be displaced and not found in its normal posterolateral position. The most sensitive finding in excluding testicular torsion is the unilateral presence of the cremasteric reflex. Testicular torsion has, however, been reported in the setting of an intact cremasteric reflex. Although commonly associated with testicular torsion, the absence of an ipsilateral cremasteric reflex is a nonspecific finding and may be associated with scrotal inflammation from any cause. In addition, some healthy young males may have an underdeveloped reflex, particularly in the first few years of life. Relief of pain with elevation of the affected testicle (Prehn sign–positive for epididymitis) does not reliably distinguish torsion from epididymitis.
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In obvious cases of testicular torsion, emergent urologic consultation and surgical exploration are essential. With acute torsion, testicular salvage is related to the duration of symptoms before surgical detorsion. Excellent salvage rates are expected with <6 hours of symptoms, but salvage declines rapidly thereafter. There are no readily available clinical or laboratory parameters to judge the degree or duration of testicular ischemia. Therefore, no matter how long the patient has been symptomatic, a rapid evaluation, including emergency scrotal exploration if necessary, should be performed. Doppler US and radionuclide scintigraphy are two imaging modalities used to evaluate patients with equivocal clinical presentations. Both may be useful, but their routine clinical use is limited by timely availability and operator experience in interpreting the images, particularly for radionuclide scintigraphy. These studies are considered "positive" for testicular torsion when they demonstrate absent or clearly reduced ipsilateral intratesticular blood flow, and "negative" when flow is normal or increased. Older duplex US studies report sensitivities ranging from 69% to 90% and specificities ranging from 98% to 99% for testicular torsion1; however, a 2013 prospective study found a sensitively of only 83%.32 Importantly, partial torsion may reveal falsely reassuring blood flow in an ischemic testicle. Likewise, normal or increased flow may be seen in a high-risk testicle following spontaneous detorsion. Gray-scale US imaging of the spermatic cord itself assessing for coils or kinks may aid in diagnosis. US findings need to be interpreted with caution in the context of the overall clinical picture. US has the advantage of demonstrating scrotal anatomy, which may indicate an alternative diagnosis. Within these limitations, testicular imaging modalities, when used in equivocal cases, can be very helpful tools.1
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For emergency or preoperative treatment, consider manual detorsion of the affected testis. Explain to the patient that detorsion is a painful procedure but successful detorsion will help to relieve the presenting pain. Most testes twist in a lateral to medial fashion (two thirds of cases); therefore, detorsion initially should be done in a medial to lateral motion.33 Detorsion is typically done in a manner similar to opening a book (Figure 93-7A). If one were to stand at the patient's feet, the patient's right testis would be rotated in a counterclockwise fashion and the patient's left testis in a clockwise fashion (Figure 93-7B). The initial attempt should include one and one-half rotations (540 degrees). Any relief of pain is a positive end point, and the success of the maneuver can be assessed with Doppler US, demonstrating restoration of blood flow. An occasional patient will require manipulation beyond the initial one and one-half rotations. A worsening of the patient's pain suggests that detorsion should then be done in the opposite direction (one third of cases). Successful detorsion converts an emergent procedure to an elective one. The timing of the elective surgical correction should depend on the patient's compliance and responsibility.
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Young boys may present to the ED with nonspecific abdominal pain suggestive of gastroenteritis only to return 1 to 2 days later with a diagnosis of testicular torsion. Whether these patients had undisclosed testicular torsion at their initial evaluation is not known, but consider testicular torsion in the differential diagnosis of any male presenting with abdominal pain or vomiting.
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The four testicular appendages—appendix testis, appendix epididymis, paradidymis (organ of Giraldes), and vas aberrans—have no known physiologic function. These pedunculated structures are capable of torsion and, in prepubertal boys, probably twist more often than the testes, with the appendix epididymis and appendix testes accounting for approximately 8% and 90% of appendage torsion, respectively. Presenting symptoms, although similar to testicular torsion, classically lack the systemic symptoms of nausea and vomiting. If the patient is seen early, with the pain localized to the upper pole of the testis or epididymis, a blue spot may be observed through the scrotal skin—the "blue dot sign." This "sign" is pathognomonic for torsion of the appendix testis or epididymis. If the diagnosis can be assured and normal intratesticular blood flow to the involved testis is confirmed by color Doppler US, surgical exploration is not necessary. Torsion of an appendage is usually self-limiting and best managed with analgesics, bed rest, supportive underwear, and reassurance, with the expected symptom resolution within 3 to 5 days. If late in the process and testicular swelling is present, or if the color Doppler US is equivocal, then urologic consultation and surgical exploration are needed to exclude testicular torsion.1
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The onset of pain in epididymitis or epididymo-orchitis is usually gradual. Bacterial infection is the most common cause, and the type of infection tends to depend on age. In young boys, epididymitis or epididymo-orchitis is commonly associated with sterile reflux of urine, but may be due to coliform bacteria, often associated with congenital anomalies of the lower urinary tract. Other considerations include increases in abdominal pressure from lifting or straining, which promote urinary reflux into the tail of the epididymis and subsequent inflammation. In young men <35 years old, epididymitis is due primarily to sexually transmitted diseases or associated complications (i.e., urethral stricture). Consider fungal or coliform infection of the lower urinary tract in addition to the more common sexually transmitted disease organisms in the setting of anal insertive intercourse. In men >35 years old, epididymitis is more commonly caused by common urinary pathogens, such as Escherichia coli and Klebsiella, or sexually transmitted diseases. In elderly men with epididymitis and urinary tract infection, consider associated benign prostatic hypertrophy or urethral stricture. Large residual urine volume (>50 to 100 mL urine) suggests outlet obstruction as the cause of the patient's infection (see chapter 92, "Acute Urinary Retention"). Chemical epididymitis can occur due to reflux of sterile urine and should be considered as a cause of prolonged symptoms despite appropriate antibiotic treatment.
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Epididymitis may cause lower abdominal, inguinal canal, scrotal, or testicular pain alone or in combination. The retrograde progression of infection from the prostatic urethra to the epididymis explains the location and progression of pain. Epididymitis represents a more advanced GU tract infection when compared with urethritis. Patients with epididymitis are more prone to lower urinary tract voiding discomfort and may note transient pain relief in the recumbent position with scrotal elevation. Initially, isolated firmness and nodularity of the affected globus minor are noted on examination. As the disease progresses, the sulcus between the epididymis and testis becomes obliterated, and the inflammatory epididymal mass may become contiguous with the testis, producing a large, tender scrotal mass (epididymo-orchitis) that may be difficult to differentiate from testicular torsion or abscess.
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Urinalysis may show pyuria in about half of patients. Obtain a specimen for gonorrhea and Chlamydia if urethral discharge is present, or in patients <35 years old. Obtain urine culture in children and elderly men. Adjunctive diagnostic modalities, such as color flow duplex Doppler sonography or radionuclide scintigraphy, will demonstrate increased or preserved blood flow to the testes. A reactive hydrocele may be seen on US.
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Most cases of epididymitis can be managed with oral antibiotics (Table 93-2).34 Admission criteria for epididymitis include fever and clinical toxicity, which can be indicative of epididymal or testicular abscess formation. The ambulatory patient should wear a scrotal supporter, being careful not to lift heavy objects or strain when having a bowel movement, both of which will increase intra-abdominal pressure and exacerbate the inflammatory cycle. A urologist will need to reevaluate the patient in 5 to 7 days and then ultimately decide when the patient may return to work based on his job description (i.e., a sedentary worker would be able to return sooner than a laborer).
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Isolated orchitis, or inflammation of the testicle, is quite rare and usually occurs in conjunction with other systemic infections, such as mumps or other viral illnesses (coxsackie virus, Epstein-Barr virus, varicella, or echovirus). Mumps orchitis presents with unilateral involvement in 70% of cases, followed by contralateral involvement in 1 to 9 days. Bacterial orchitis is almost always associated with epididymitis. Orchitis in immunocompromised patients can be due to mycobacteriosis, cryptococcosis, toxoplasmosis, or candidiasis. Patients with orchitis usually present with testicular tenderness and swelling over a few days in duration. The diagnosis is primarily clinical using history and physical examination, but US can exclude testicular torsion or abscess. Treatment for acute episodes starts with antibiotic coverage as listed above for epididymitis; IV antibiotics should be considered for patients with abnormal vital signs.34 Immunocompromised patients or patients with risks for tuberculosis (exposure, uncontrolled human immunodeficiency virus, or diabetes) require admission if they have abnormal vital signs or, if not, referral to urology and/or infectious disease for further management.
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TESTICULAR MALIGNANCY
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The hallmark of testicular carcinoma is an asymptomatic testicular mass with firmness or induration. Ten percent of tumors will present with pain secondary to acute hemorrhage within the tumor. Metastatic testicular tumors can be insidious and must be suspected in any male with unexplained supraclavicular lymphadenopathy, abdominal mass, or chronic nonproductive cough from a lung metastasis. Testicular examination may disclose a primary tumor. Any unexplained testicular mass must be approached as a possible tumor with urgent urologic referral.