A spermatocele is a benign cystic accumulation of sperm that arises from the head of the epididymis. Although often disconcerting to the patient when noticed, these lesions are benign. Spermatoceles can develop in varying locations, ranging from the testicle itself to locations along the course of the vas deferens. Nevertheless, in common usage, spermatoceles are intrascrotal, paratesticular cystic collections of sperm that arise from the epididymis.
Usually smooth, soft, and well-circumscribed, spermatoceles are broadly described as scrotal masses. The differential diagnoses include hydrocele, varicocele, hernia, simple epididymal cyst, and neoplasm. History, examination, and ultrasonography can aid in the differentiation.
Spermatoceles typically arise from the caput (head) of the epididymis, which is located on the superior aspect of the testicle. Conversely, hydroceles are fluid collections that cover the anterior and lateral surfaces the testicle. A varicocele is a dilated plexus of veins along the spermatic cord. A hernia results from persistent patency of the processus vaginalis allowing intraabdominal contents to pass into the abnormal intrascrotal peritoneal extension.
In contrast to spermatoceles, both varicoceles and hernias may enlarge with the increased intraabdominal pressure generated during Valsalva. Epididymal cysts are often grouped with spermatoceles, and the two may be impossible to differentiate based on gross anatomy. In contrast to the epididymal cyst, spermatocele fluid typically contains sperm.
The term spermatocele is derived from the Greek spermatos (sperm) and kele (cavity or mass). It has been recognized for more than 100 years.
A spermatocele is a cystic accumulation of sperm that contains fluid typically arising from the head of the epididymis. It is a common benign finding on routine physical examination and is usually smaller than 1 cm. Less commonly, they may enlarge to several centimeters. Pain, discomfort, or resultant significant scrotal distortion may prompt surgical intervention.
Spermatoceles have been incidentally identified in 30% of patients undergoing scrotal ultrasonography for other reasons. The exact prevalence of this common condition has not been defined.
The etiology of spermatoceles in humans remains undefined. Multiple etiologies have been proposed, although none is universally accepted. Some hypotheses include that spermatoceles may arise from efferent ductules, may be aneurysmal dilations of the epididymis, or may be dilation secondary to distal obstruction. In a mouse model of spontaneous spermatocele, distal efferent ducts were found to be occluded by agglutinated germ cells.
The specific pathophysiology remains to be elucidated. Although distal obstruction has been theorized as a potential mechanism, the presence of motile sperm in up to 80% of spermatoceles suggests maintenance of proximal patency.
Typically, spermatoceles are asymptomatic. They are often incidental findings on testicular self-examination or routine physical examination. As they usually arise from the head of the epididymis, they are found superior to the testicle. They are smooth and spherical and transilluminate on examination. Failure to transilluminate suggests a solid lesion, which warrants further evaluation, including scrotal ultrasonography and possible inguinal exploration.
Surgical intervention is not indicated for the incidental asymptomatic spermatocele. However, if discomfort, pain, or progressive enlargement is bothersome to the patient, discussion regarding excision may ensue.
The first image below demonstrates a cross-section of the testicle, epididymis, and vas deferens. The second image is an illustration of a spermatocele. The last two images are intraoperative photographs of a large symptomatic spermatocele.
A sagittal section of the testicle. Idiopathic obstruction of the epididymal ducts is one hypothesis that explains the formation of spermatoceles.
Diagram of a spermatocele.
Spermatocele as seen prior to incision.
Intraoperative view of spermatocele with adjacent testicle and spermatic cord.
Needle aspiration of a spermatocele should be avoided, as it may lead to infection, spillage of irritating sperm within the scrotum, and reaccumulation of the spermatocele. Spermatocelectomy may be offered to symptomatic patients who are reasonable surgical candidates. Anticoagulation is a relative contraindication. Sclerotherapy is usually not performed in reproductive-aged men because of the risk of chemical epididymitis and resultant epididymal damage, which may contribute to future infertility.
No laboratory studies are mandated in the evaluation of an uncomplicated asymptomatic spermatocele. If the patient reports scrotal pain, a urinalysis is indicated to rule out epididymitis.
The preferred modality for evaluating scrotal pathology is high-resolution scrotal ultrasonography. Although many experienced physicians may be comfortable making the diagnosis based on history and physical examination, ultrasonography is useful to confirm the suspected diagnosis and to rule out any additional intratesticular pathologic condition.
Spermatoceles usually appear as cystic lesions that arise from the epididymal head; less commonly, they appear as an intratesticular lesion attached to the mediastinum testis. They are hypoechoic with posterior acoustic enhancement and usually cannot be differentiated from an epididymal cyst based on ultrasonographic findings. Occasionally, a spermatocele may have internal echoes within the cyst. An example of a spermatocele observed on scrotal ultrasonography is shown in the image below.
A scrotal ultrasound demonstrating a spermatocele visible to the left of a normal testis.
Color Doppler may reveal a "falling snow," resulting from internal echoes moving away from the transducer.
Microscopic examination reveals a fibromuscular wall that is lined by cuboidal epithelium, as illustrated in the image below.
Microscopic view of spermatocele lined with cuboidal epithelium.
A gross specimen of a spermatocele is shown in the images below.
Intraoperative view of spermatocele with adjacent testicle and spermatic cord.
Spermatocele after complete excision.
No specific medical therapy is indicated for treatment of a simple spermatocele. Oral analgesics may be prescribed for symptomatic relief. If an underlying epididymitis is responsible for discomfort, antibiotics may be indicated. Observation is usually used for simple, small asymptomatic spermatoceles.
Spermatocelectomy via a transscrotal approach is the primary operative intervention for spermatocele, and it may be offered to any reasonable surgical candidate. Systemic anticoagulation and desire to father children are relative contraindications.
Sclerotherapy is an alternative to excision, but results appear to be less effective. Sclerotherapy is usually reserved for men who have no desire for future paternity, because of the risk that ensuing chemical epididymitis and resultant epididymal damage may impair fertility. Because aspiration of spermatocele alone is associated with a high recurrence rate, a sclerosing agent is used to cause coaptation of the walls of the cyst.
Sclerosant materials that have been used, all with degrees of success varying from 30%-100%, have included the following:
With polidocanol instillation, success rates of 34-59% were noted after a single instillation. With repeated treatments, up to 89% were ultimately considered successful. Comparative trials have not established any one agent as a superior spermatocele sclerosing agent. Similarly, no standard dosing for maximal benefit is currently available.
Spermatocelectomy is typically performed on an outpatient basis, with either regional or general anesthesia. The choice is based on the preference of the patient, surgeon, and anesthesiologist. The patient must be counseled regarding the risks of infertility, as well as the more common complications of hematoma, infection, swelling, recurrence, and pain.
Sclerotherapy is performed on an outpatient basis after the potential complications are discussed. The administration of anesthesia is provided locally, although the timing may vary according to surgeon preference. Some have reported administration at the puncture site prior to initiating the procedure, while others instill the anesthetic during the instillation of the sclerosant, after aspiration has occurred.
The scrotum is prepared and sterilely draped. In addition, a folded sterile towel placed beneath the scrotum supports and elevates it into the surgical field. Either a vertical median scrotal raphe or a transverse hemiscrotal incision may be used. The dissection is continued to the level of the tunica vaginalis with electrocautery. The testicle, epididymis, and spermatocele may then be delivered from the dartos with gentle blunt dissection, leaving the tunica intact.
Alternatively, some surgeons instead incise the tunica vaginalis in situ and deliver the testicle and epididymis out of the wound. Using both blunt and sharp dissection, the spermatocele is isolated from the body of the epididymis, and, typically, a narrow neck is found attaching the spermatocele to the rest of the epididymis. This neck is ligated with a 3-0 absorbable suture and divided.
If a multiloculated spermatocele is present or the neck is not readily found, the spermatocele is ideally kept intact while it is gently dissected away from normal tissue. Preventing perforation may be difficult because of the adherent nature of surrounding tissues but is advantageous, as it simplifies dissection and limits the spillage of potentially locally irritating sperm. When a plane cannot be readily developed, some advocate excision of adjacent normal epididymis with the specimen (partial epididymectomy); however, this increases the risk of epididymal obstruction.
Once the spermatocele has been dissected free and removed, hemostasis must be obtained. Because of the capacious nature of the scrotum, bleeding does not readily tamponade. Dramatic postoperative hematomas can result.
After achieving hemostasis, the tunica/dartos layer is closed with a 2-0 or 3-0 absorbable running suture, and the skin is closed with 3-0 absorbable suture in a subcuticular, interrupted, or running stitch. Dry gauze fluffs and an ice pack are placed on the scrotum, and the patient is discharged with a scrotal supporter.
The scrotum is prepared and sterilely draped. The scrotal skin is punctured at the most prominent point of protrusion with a 16-gauge intravenous cannula. Fiber optic lighting or ultrasound guidance may be used at the discretion of the surgeon. If the spermatocele is multicystic, ultrasound guidance may also be used to ensure that all cavities are aspirated. The needle is withdrawn from the plastic sheath of the cannula, and all of the cystic fluid is withdrawn with a syringe. Manual manipulation of the scrotum is needed to ensure complete evacuation of the spermatic fluid.
A sclerosant is then instilled through the cannula after the spermatocele fluid has been evacuated. The amount and type of sclerosant varies, depending on an individual practitioner's preference. The amount of sclerosant used depends on the amount of fluid aspirated from the spermatocele and the adopted technique. Volumes for one such technique are shown in Table 1.
Table 1. Volume of Sclerosant Solution Used for Sclerotherapy
After sclerosant installation, the cannula is removed and the scrotum massaged by hand to ensure adequate distribution of the sclerosant solution throughout the injection cavity.
Postoperatively, patients are encouraged to continue scrotal support, using an athletic supporter for a minimum of 48 hours after discharge. Additionally, gentle scrotal elevation while the patient is supine may decrease the risk of uncomfortable postoperative edema. Intermittent application of cold or ice packs to the dressing is commonly used. Oral analgesics (eg, acetaminophen and codeine [Tylenol #3] or hydrocodone and acetaminophen [Vicodin] 1-2 tabs PO q4-6h prn) should provide adequate postoperative pain relief. Patients are instructed to keep the dressing in place, to allow the wound to dry for 48 hours, and to avoid strenuous activity for 2 weeks.
Direct pressure to the scrotum should be avoided. Patients often do not require narcotic analgesics and, after being observed for 1-3 hours, may be discharged without any physical restrictions.
Patients are scheduled to return 2-6 weeks postoperatively to evaluate the wound and address any additional concerns.
Each patient is assessed 1 month after surgery and reassessed at 4-6 months. If the spermatocele has recurred or is bothersome, imaging studies are obtained, and, if a spermatocele is present, the patient is offered an additional course of sclerotherapy or surgical excision.
For excellent patient education resources, visit eMedicineHealth's Men's Health Center. Also, see eMedicineHealth's patient education article The Male Anatomy.
As should be routinely discussed preoperatively, any invasive surgical procedure has inherent risks. Epididymal injury and obstruction may occur. Gross injury to the epididymis, confirmed histologically based on its presence in the spermatocele specimen, has been reported in as many as 17% of patients. Inadvertent epididymal obstruction without excision certainly may exceed this. Infertility may result from either injury. The authors routinely counsel patients that infertility may result. Additional risks include scrotal hematoma formation, superficial wound infection, swelling, and recurrence of the spermatocele.
Following sclerotherapy, potential complications include epididymal injury, infertility, bleeding, infection, chemical epididymitis, and spermatocele recurrence. Postprocedure, minor pain was noted in 10%, moderate pain in 4%, and severe pain in approximately 3% of patients. A 65% success rate is quoted, although patients with large or multiloculated spermatoceles were more likely to have a recurrence that required additional intervention. Finally, as result of the chemically induced inflammatory reaction, scrotal wall thickening may develop postsclerotherapy.
The expected outcome and prognosis of spermatocelectomy are excellent. A recent study revealed that of patients who underwent excision of an uncomfortable spermatocele, 94% were rendered pain-free. Spermatocelectomy remains the best surgical treatment for symptomatic spermatoceles.
Conversely, although sclerotherapy may carry a decreased incidence of wound complications and potentially lower associated costs, its efficacy is generally considered inferior.
To date, no prospective randomized trial has compared the outcomes of spermatocelectomy with those of sclerotherapy. Similarly, sclerosing agents have not been subjected to this degree of evaluation.
Although surgical specimens are often sent for pathology analysis after spermatocelectomy, it may be of little clinical benefit. In a retrospective study of 57 spermatocelectomy cases and 102 hydrocelectomy cases, none of the pathology specimens showed any indication of malignancy, and the estimated direct cost of these analyses totaled $49,449. in order to demonstrate whether one agent or dosing regimen is superior to others.
Fluid Aspirated from Spermatocele
(Volume in mL)
Sclerosant Solution Injected
(Volume in mL)
< 20 2 20-50 3 51-100 5 101-200 10 201-300 15 301-400 20 401-800 25 >800 30