Scrotal cysts are fluid-filled or material-filled sacs that develop either within the scrotal skin or deeper inside the scrotum alongside the testicle and epididymis. They arise from several distinct mechanisms depending on where they form: skin-level cysts typically result from blocked hair follicles or glands, while internal cysts like epididymal cysts and spermatoceles develop from the tubular structures that store and transport sperm. The vast majority are benign, and many require no treatment at all unless they grow large enough to cause discomfort or concern.
Skin-Level Scrotal Cysts
The most visible scrotal cysts are those that form in the skin itself. These are commonly called sebaceous cysts, though that term is a bit of a misnomer. The proper name for most of them is epidermoid cyst (or epidermal inclusion cyst), and they form when a hair follicle opening becomes plugged with keratin, the tough protein that makes up the outer layer of your skin. Once plugged, dead skin cells accumulate inside the blocked follicle, gradually expanding into a firm, round lump just beneath the surface.1PubMed Central. Multiple Swellings Over the Scrotum: Epidermal Inclusion Cysts Scrotal skin is particularly prone to these because it has a high density of hair follicles and sweat glands, and the warm, moist environment makes blockages more likely.
Epidermoid cysts on the scrotum can be solitary or appear in clusters. A person might notice a single pea-sized bump, or a dozen of them scattered across the scrotal surface. They are usually painless and grow slowly over months or years. They feel firm and slightly mobile under the skin, and if squeezed (not recommended), they may produce a thick, whitish, cheese-like material made of compacted keratin. Some epidermoid cysts grow impressively large if left alone. One published surgical case involved a giant scrotal epidermoid cyst containing roughly 600 grams of keratinous material, which was successfully removed while preserving the underlying testicle.2PubMed Central. Giant Scrotal Epidermoid Cyst Containing 600 g of Keratinous Material: A Rare Testis-Preserving Surgical Excision
A less common skin-level condition is steatocystoma multiplex, where numerous small cysts develop from a malformation of the gland-and-follicle unit in the skin. These cysts contain oily sebum rather than keratin. They tend to appear in young adulthood as multiple firm, yellow-to-skin-colored bumps, and they can show up on the scrotum as well as other body areas.3PubMed Central. Steatocystoma Multiplex of Scrotum Steatocystoma multiplex can be sporadic or run in families.4Clinical Nuclear Medicine. Increased FDG Uptake in Scrotal Steatocystoma Multiplex With Calcification
Epididymal Cysts and Spermatoceles
Inside the scrotum, the most common cysts arise from the epididymis, the coiled tube sitting behind each testicle that collects and stores sperm. These fall into two closely related categories. An epididymal cyst is a simple fluid-filled sac attached to the epididymis. A spermatocele is essentially the same thing except the fluid contains sperm cells. Both present as painless lumps that you can feel separate from the testicle itself, usually near the top or behind it.
The exact cause of most epididymal cysts and spermatoceles is not fully understood. They appear to develop when one of the tiny tubules in the epididymis becomes blocked or dilated, allowing fluid to pool and form a cyst. Prior infection, injury, or inflammation of the epididymis may contribute in some cases, but many arise with no identifiable trigger. They are extremely common: incidental epididymal cysts show up frequently on scrotal ultrasounds performed for unrelated reasons, especially in men over 40.
Fluid analysis shows that spermatoceles have a slightly different internal environment compared to simple epididymal cysts. Spermatocele fluid contains various sperm forms and has higher levels of certain inflammatory signaling molecules than epididymal cyst fluid, even in the absence of actual immune cells like neutrophils.5PubMed. Pro-inflammatory cytokine response of the fluid contents of spermatoceles and epididymal cysts In practical terms, though, both types behave the same way clinically: they are benign, usually painless, and rarely need intervention.
Other Internal Cystic Lesions
Beyond epididymal cysts and spermatoceles, a few other cystic structures can appear inside the scrotum. Cysts of the tunica albuginea, the tough outer capsule of the testicle, are typically small and discovered incidentally on ultrasound. In one study comparing cystic scrotal masses, all tunica albuginea cysts were palpable as small bumps, and imaging confirmed they were simply fluid-filled rather than solid.6PubMed. Testicular cysts: differentiation with US and clinical findings Intratesticular cysts, those arising within the testicle tissue itself, are rarer and are almost never palpable. The same study found that the vast majority of non-cancerous intratesticular cysts were solitary and located near the margin of the testicle, a pattern that helps distinguish them from testicular tumors, which tend to have multiple cystic spaces mixed with solid components.
Hydroceles, which are collections of fluid between the layers of tissue surrounding the testicle, are sometimes grouped alongside scrotal cysts in conversation. They are technically a fluid collection rather than a true cyst, but they can feel similar on self-exam and are evaluated and sometimes treated in overlapping ways.
How Scrotal Cysts Are Diagnosed
Most scrotal cysts are first noticed during a self-exam or a routine physical. A doctor can often tell a simple cyst from a solid mass by feel alone: cysts are smooth, mobile, and you can often shine a light through them (a technique called transillumination). Scrotal skin cysts are usually diagnosed on appearance without further workup.
When there is any doubt, ultrasound is the go-to imaging tool. It can reliably distinguish a simple cyst from a solid mass, show the exact size and location, and determine whether the cyst is attached to the epididymis, the testicle, or the scrotal wall.7PubMed Central. Cystic lesions and scrotal fluid collections in adults: Ultrasound findings MRI is rarely needed, but can help when ultrasound results are ambiguous.8European Society of Radiology. Intra- and extra-testicular cystic lesions: US and MRI findings
The reason doctors take scrotal lumps seriously is that a hard, non-transilluminant mass could be testicular cancer. The reassuring news is that most cystic lesions seen on ultrasound are clearly benign. The combination of how the lump feels on exam and what it looks like on imaging usually makes the diagnosis straightforward, and biopsy is almost never required for a simple cyst.
When Treatment Is Not Needed
For both skin-level cysts and internal epididymal cysts, the first-line approach is often no treatment at all. Small, painless cysts that are clearly benign on exam or imaging can be monitored. Many epididymal cysts in particular remain stable for years, and some resolve on their own.
In children and adolescents, conservative management is especially favored. A study of pediatric epididymal cysts found that watchful waiting led to complete resolution in about half the patients. Some cysts shrank, though a few did grow or multiply during follow-up.9Frontiers in Pediatrics. Epididymal cysts in children: frequency, clinical characteristics, and management strategies The main trigger for intervention is when a cyst causes persistent pain, grows large enough to be bothersome, or creates diagnostic uncertainty about whether it could be something more serious.
Treating Scrotal Skin Cysts
When epidermoid cysts on the scrotal skin become symptomatic, infected, or cosmetically concerning, surgical excision is the standard treatment. The goal is to remove the entire cyst wall intact, because leaving fragments behind tends to lead to recurrence. For men with many clustered cysts, a broader excision of the affected scrotal skin can be performed. One case series of patients with multiple scrotal nodules found that removing sections of affected scrotal wall under local anesthesia produced excellent cosmetic results, no significant complications, and no recurrence over a year of follow-up.10PubMed. Multiple nodules of the scrotum: histopathological findings and surgical procedure. A study of five cases
The scrotal skin is remarkably elastic and forgiving. Even when substantial amounts of tissue are removed, the scrotum can be reconstructed with good functional and cosmetic results. In the case of the giant epidermoid cyst mentioned earlier, the surgeon removed the entire cyst, excised the redundant skin, and performed a scrotoplasty that preserved the testicle and restored a normal appearance.2PubMed Central. Giant Scrotal Epidermoid Cyst Containing 600 g of Keratinous Material: A Rare Testis-Preserving Surgical Excision
Treating Epididymal Cysts and Spermatoceles
For internal cysts that do need treatment, there are two main routes: aspiration with sclerotherapy or surgical removal.
Aspiration and Sclerotherapy
Aspiration means draining the cyst with a needle. The problem with aspiration alone is that the cyst almost always refills. To prevent that, doctors often inject a sclerosing agent, a chemical that irritates the cyst lining and causes it to scar shut. One commonly used agent is alcohol. In a study using this approach, about three-quarters of spermatoceles and epididymal cysts resolved after a single aspiration-and-sclerotherapy procedure. When a second treatment was offered for persistent cases, all remaining patients achieved resolution, giving an overall success rate of roughly 85% with the complication rate staying low.11PubMed. Aspiration and sclerotherapy of hydroceles and spermatoceles/epididymal cysts with 100% alcohol Longer-term data from another study showed an initial success rate of about three-quarters, climbing to over 90% with repeated treatments over a median follow-up of about two and a half years.12PubMed. Long-term experience with sclerotherapy for treatment of epididymal cyst and hydrocele
Sclerotherapy is appealing because it is minimally invasive and can be done in an office or outpatient setting. The main downside is that it sometimes requires more than one session, and there is a theoretical concern about scarring in the epididymis that could affect fertility. For this reason, sclerotherapy is generally reserved for men who are not planning future children or who are not candidates for surgery.
Surgical Excision
Spermatocelectomy or epididymal cyst excision is the more definitive option. Traditional open surgery involves making a small scrotal incision, identifying the cyst, and dissecting it away from the epididymal tubules. The concern with older open techniques was inadvertent damage to the epididymis, which could obstruct the sperm pathway and harm fertility.
Microsurgical techniques have changed the picture. Using an operating microscope, surgeons can dissect the cyst from individual epididymal tubules with far greater precision. In a study of microsurgical spermatocelectomy, no cyst specimens contained epididymal tissue (confirming accurate dissection), no patient experienced decreased sperm counts afterward, and none had cyst recurrence or testicular atrophy over an average follow-up of about 17 months. All patients who had preoperative pain reported improvement.13PubMed. Microsurgical spermatocelectomy: technique and outcomes of a novel surgical approach A more recent study of a similar single-tubule microsurgical technique confirmed these findings, with no recurrence, no epididymal tissue in pathology specimens, and no decrease in sperm counts. That study actually found a statistically significant improvement in sperm motility after surgery.14PubMed. Microscopic single-tubule technique for spermatocelectomy in cases of spermatocele: a rarely used surgical method and ıts outcomes
Surgical Risks and Complications
No surgery is risk-free, and scrotal surgery carries a few specific complications worth knowing about. A population-based review of outpatient hydrocelectomy and spermatocelectomy found an overall complication rate of about one in five patients. The most common problems were infection or abscess formation (around 9%), persistent swelling or treatment failure (around 9%), and chronic pain (under 1%).15PubMed. A population based assessment of complications following outpatient hydrocelectomy and spermatocelectomy Another large study of elective benign scrotal surgery reported comparable numbers: hematoma at 9%, infection at 5%, recurrence of swelling at about 7%, and chronic pain at a very low rate.16PubMed. Complications and risk factors in elective benign scrotal surgery
These complication rates reflect a mix of surgical techniques, including both traditional open methods and newer microsurgical approaches. The microsurgical studies referenced earlier reported substantially lower complication rates, with only isolated cases of hematoma or infection and no recurrences. The tradeoff is that microsurgical procedures take longer and require specialized equipment and training, so they are not universally available.
Fertility and Scrotal Cysts
One of the most common worries men have about epididymal cysts is whether they affect fertility. The evidence is reassuring. A study comparing men with epididymal cyst lesions to men without them found no significant difference in semen volume, sperm concentration, motility, morphology, total motile sperm count, or hormone levels. Even the size and whether cysts appeared on one or both sides made no difference to any semen parameter.17PubMed. Epididymal Cyst Lesions Are Not Associated With Impaired Semen Parameters Among Men Presenting for Fertility Evaluation An earlier study reached the same conclusion: epididymal cysts were not associated with infertility.18PubMed Central. Epididymal Cysts: Are They Associated With Infertility?
The fertility question also applies to treatment. If surgery is needed, the concern is that removing a cyst could damage the epididymal duct and block sperm flow. With microsurgical cystectomy, the data is encouraging. One study found no significant change in sperm count, motility, or morphology at one-year follow-up, and men with larger cysts (over 2.5 centimeters) actually saw improvements in sperm count after surgery.19PubMed. Microsurgical Epididymal Cystectomy does not Impact Upon Sperm Count, Motility or Morphology and is a Safe and Effective Treatment for Epididymal Cystic Lesions (ECLs) in Young Men With Fertility Requirements The likely explanation is that large cysts can physically compress or stretch the epididymal tubules, and removing them relieves that pressure.
Scrotal Calcinosis and the Cyst Connection
Some men develop hard, chalky nodules in the scrotal skin, a condition called scrotal calcinosis. For years this was considered “idiopathic,” meaning no one knew what caused it. But pathological examination has shown that many of these calcified nodules are actually the end stage of epidermoid cysts. The cyst’s keratin contents calcify over time, and in some cases the cyst wall ruptures, triggering a granulomatous inflammatory reaction that deposits calcium throughout the surrounding tissue.20JAMA Dermatology. Scrotal Calcinosis: Dystrophic Calcification of Epidermoid Cysts Scrotal calcinosis is painless and benign. It is treated surgically only when the lumps become numerous enough to be cosmetically bothersome or uncomfortable.
Epididymal Cysts in Adolescents
Epididymal cysts are often thought of as an adult finding, but they do occur in children and teenagers, where they are more likely to be overlooked or misidentified. Most adolescent cases are painless and can be managed conservatively, with aspiration or elective surgery reserved for cysts that persist or grow. The rare but important exception is when an epididymal cyst undergoes torsion, twisting on itself and cutting off its blood supply. One case report described an adolescent whose epididymal cyst had twisted 720 degrees and was accompanied by a simultaneous 180-degree torsion of the testicle itself, requiring emergency surgery.21PubMed Central. Case Report: Adolescent epididymal cysts: three management approaches including a rare synchronous epididymal cyst and testicular torsion The takeaway for parents and teenagers is that a painless lump near the testicle is usually benign, but sudden onset of scrotal pain demands urgent medical evaluation regardless of whether a cyst was already known to be present.
When Scrotal Cysts Signal Something Else
In the overwhelming majority of cases, a scrotal cyst is exactly what it appears to be: a benign, fluid-filled structure that poses no threat. But there are a couple of situations where cysts can be a clue to a broader condition.
Von Hippel-Lindau disease (VHL) is a rare inherited syndrome that predisposes people to tumors and cysts in multiple organs. Among men with VHL, over half have been found to have abnormalities in the head of the epididymis on imaging, often bilateral, that are suggestive of epididymal cystadenomas.22PubMed. Epididymal cystadenomas in von Hippel-Lindau disease These are not simple cysts but rather benign tumors with a cystic component. A young man presenting with bilateral solid-feeling epididymal masses, especially with a family history of VHL-associated findings like kidney tumors or retinal angiomas, warrants further investigation.
On the imaging side, the main concern when any cystic mass is found inside the scrotum is ruling out a cystic testicular tumor. As noted earlier, non-cancerous intratesticular cysts tend to be solitary and located near the edge of the testicle, while cystic tumors typically show a mix of cystic spaces and solid components.6PubMed. Testicular cysts: differentiation with US and clinical findings This distinction is usually clear on ultrasound, which is one reason the test is so routinely ordered for any new scrotal lump. A purely cystic, thin-walled, anechoic structure on ultrasound is almost certainly benign. A complex mass with solid portions is not, and it gets a very different workup.