Testicular microlithiasis is the presence of numerous small calcium deposits, or calcifications, located within the testicles. These deposits are typically tiny, measuring only a few millimeters in size, and are found inside the seminiferous tubules where sperm production occurs. The condition is generally without symptoms and is most often discovered accidentally when a person undergoes an ultrasound for an unrelated issue, such as pain, swelling, or infertility. While the finding of these calcifications is usually benign, the association with a potentially more serious condition, like testicular cancer, often causes significant concern for patients, which medical professionals now work to address through clear guidelines.
How Testicular Microlithiasis is Identified
The diagnosis relies exclusively on high-resolution scrotal ultrasound imaging, as the calcifications are too small to be felt. On an ultrasound scan, the deposits appear as multiple small, bright spots, medically termed echogenic foci. These spots are typically less than 3 millimeters and do not produce an acoustic shadow, which distinguishes them from other calcifications.
The visual presentation of numerous bright spots scattered across the testicular tissue is sometimes described as a “starry sky” pattern. The condition is formally diagnosed when five or more microcalcifications are visible within a single field of view on the ultrasound image. If fewer than five are seen, the condition may be classified as limited microlithiasis. The diagnosis is based purely on this physical appearance and requires no other testing.
Understanding the Link to Testicular Cancer
The main concern regarding testicular microlithiasis is its association with testicular germ cell tumors, the most common form of testicular cancer. Historically, this led to the belief that microlithiasis was an independent risk factor, but current medical understanding has shifted. Studies show that while men with microlithiasis have a higher relative risk compared to the general population, the absolute risk is still low, especially when microlithiasis is the only finding.
The clinical significance of the calcifications changes dramatically when other risk factors for testicular cancer are present. These other risk factors include a history of cryptorchidism (undescended testicle), having a prior testicular tumor, a family history of the disease, or testicular atrophy (a small testicle). For instance, one study suggests that the risk of a testicular tumor in patients with microlithiasis and additional infertility is multiplied by 10 to 40 times.
In cases where testicular microlithiasis is found without any other coexisting risk factors, it is no longer considered a strong independent predictor of testicular cancer. Researchers believe that microlithiasis is simply a marker for an underlying abnormality in the testicle, which may or may not be the precursor to cancer. The challenge is that most studies have focused on men already receiving an ultrasound for symptoms, which may overestimate the prevalence of cancer. Current recommendations reflect the understanding that isolated microlithiasis carries a very small risk, whereas its presence alongside other established factors warrants closer attention.
Clinical Recommendations for Monitoring and Follow-up
No active treatment is required for the calcifications themselves, as they are benign. Medical management focuses on surveillance to ensure the early detection of potential tumor development. The specific follow-up protocol depends on whether the patient has isolated microlithiasis or additional risk factors.
For individuals with isolated microlithiasis and no other risk factors, routine repeat ultrasounds are not recommended. The primary recommendation is regular testicular self-examinations. This involves checking the testicles monthly for new lumps, size changes, or other abnormalities. Patients should contact their doctor immediately if they find unusual changes.
If microlithiasis is combined with other risk factors, such as cryptorchidism or a prior tumor in the opposite testicle, a more structured surveillance program is advised. This management involves regular self-examinations and periodic clinical check-ups with a urologist. Some guidelines recommend annual scrotal ultrasound examinations for these high-risk patients, often continuing until age 55, to monitor for concerning changes.