(1)     Introduction

Acute scrotal swelling poses one of the more challenging clinical dilemmas in medicine.  Distinguishing benign conditions from the acute scrotum is the key to managing these patients.  The acute scrotum can be defined as any condition of the scrotum or intrascrotal contents requiring emergent medical or surgical intervention.  Although rarely fatal, acute scrotal pathology can result in testicle infarction and necrosis, testicular atrophy, infertility, persistent testalgia, and significant morbidity. 

The correct diagnosis of the acute scrotum is not always obvious, but a thorough history, physical exam, and use of basic laboratory studies can aid in distinguishing benign from surgical conditions.  However, patients may present with an atypical history and physical exam.  They may often delay presenting for help until far into the course of the illness when the physical exam is obscured by scrotal edema.  Patient discomfort may limit obtaining a thorough physical exam.  Ultimately, the most important question to be addressed is whether the testicle is adequately perfused.

(2)     Differential Diagnosis

The differential diagnosis of acute scrotal swelling can be divided most easily into painful and painless categories.  The sources of painful scrotal swelling include testicular torsion, torsion of a testicular appendage, epididymitis, orchitis, an incarcerated hernia, an infarcted germ cell tumor, scrotal cellulitis and fasciitis, and post-traumatic causes.  Painless etiologies for acute scrotal swelling may include hernias, varicocoeles, hydrocoeles, spermatocoeles, epididymal cysts, and germ cell tumors of the testis.

(3)     Presentation

Testicular torsion may occur at any age and is the diagnosis that must be excluded when a patient presents with an acutely swollen scrotum.  The patient will often describe the paroxysmal onset of sharp, debilitating pain in the scrotum.  Most often there is no inciting event and the patient may describe being awakened at night with the pain.  The testicle may be described as high riding in the scrotum with associated scrotal erythema and edema.  Often there are no associated irritative voiding symptoms, burning on urination, or urethral discharge.  If the patient presents early in the course of the torsion, the exam will often confirm the diagnosis.  The testis is frequently firm to hard, fixed to the dartos and scrotal wall.  The testicle may be exquisitely tender, but this is not universal. It may be high riding in the scrotum.  The ipsilateral cremasteric reflex is almost universally absent, but if the contralateral reflex is missing, the significance of the finding is less helpful.  The spermatic cord will be foreshortened and thickened.  The epididymis may assume a medial, lateral, or anterior position.  Because of venous congestion, the testis is usually larger than the unaffected side.  Urinalysis and culture is typically normal in the early course of testicle torsion.  The diagnosis of torsion is often confirmed with Doppler ultrasound.  The absence of blood flow within the testicle is diagnostic.  Ultrasound of a recently detorsed testicle may show an enlarged testicle with increased blood flow throughout.  The key to torsion of the testicle is recognizing the presence of the torsion and immediate referral for surgical orchiopexy.  The testicle must have its blood supply returned within 6 hours to avoid permanent damage.  If the patient is suspected to have torsion of the testicle, emergent referral to the nearest facility with a surgeon capable of performing an orchiopexy is mandatory.

(4)     Manual Detorsion: Open the Book

Manual detorsion of the testicle may be attempted as a temporizing measure.  Detorsion is most frequently successful when the testicle is rotated toward the respective outer thigh.  The physician should rotate the testicle outward as if opening a book (clockwise with the right hand, counter clockwise with the left).  The testicle may need to be rotated more than 360 degrees.  Successful detorsion is characterized by significant relief of the patient’s symptoms.  The patient still must be referred for emergent surgical exploration and orchiopexy.

(5)     Torsion of a Testicular Appendage

Torsion of a testicular appendage can mimic testicular torsion, but the symptoms are often not as severe.  In patients with thin scrotal skin, the torsed appendage may present with a visible “blue dot” at the pole of the testicle.  Tenderness is usually isolated to that area and the testis is usually neither enlarged nor tender.  The epididymis is in the correct anatomic position.  There may be impressive scrotal swelling if the patient has delayed seeking medical attention.  Urinalysis and culture are generally normal early in course of the disease.  Ultrasound may be required if the diagnosis is in question.  No surgery is required.  The treatment is supportive with anti-inflammatory medications, scrotal elevation, cold packs, and rest.

(6)     Epididymitis

Epididymitis occurs more frequently than testicular torsion as males grow beyond adolescence.  Most patients will describe the gradual onset of increasingly intense pain in the testicle and scrotum for some period of time before presentation.  The pain may, however, have an acute onset, thus leading to the difficulty distinguishing this from torsion of the testicle.  Pain with epididymitis may radiate along the spermatic cord to the lower abdomen and may even reach the flank.  The patient may describe having burning on urination, irritative voiding symptoms, and a urethral discharge.  On physical exam, the epididymis is exquisitely tender, often enlarged, and scrotal edema may be present.  As the disease progresses, the epididymis may no longer be distinguishable from the testis, the cord may become thickened, and the patient may develop a reactive hydrocoele.  The pain may be diminished with elevation of the testicle (Prehn’s sign).  Laboratory studies may help to confirm the diagnosis.  A CBC may show leukocytosis with a left shift.  Urinalysis will typically show pyuria, hematuria, and bacteriuria.  Urine culture may grow coliform bacteria, neisseria species, or chlamydia.  It is always necessary to see these patients back to document full resolution of the symptoms.  Although rare, patients with testicular tumors may present with a reactive epididymitis as the only finding on exam.  Two to 4 weeks of appropriate antibiotic therapy should be enough time for an epididymitis to resolve. 

Submitted by CAPT M. Melanie Haluszka, MC, USN, LCDR Brian K. Auge, MC, USN, and LT Timothy F. Donahue, MC, USNR, National Naval Medical Center, Bethesda (1999).