MOST TESTICULAR LESIONS SMALLER THAN 1cm ARE BENIGN

April 25, 2012 (Phoenix, Arizona) — The majority of testicular lesions smaller than 10 mm are benign, and with ultrasound monitoring, unnecessary surgical intervention can be avoided, according to research presented here at the American Institute of Ultrasound in Medicine 2012 Annual Convention.

The latest technologies in high-resolution scrotal ultrasound imaging can detect lesions as small as 2 mm, but data on the natural history of such lesions are lacking.

"Previous studies have indicated that with these kind of small testicular lesions, most are benign. This may mean that we can use ultrasound to safely avoid surgical intervention in some patients," said lead author Qian Li, MD, from the Massachusetts General Hospital in Boston.

To investigate the issue and evaluate the potential benefits of active ultrasound surveillance, Dr. Li and his colleagues conducted a retrospective 11-year review of patients who underwent scrotal ultrasound for intratesticular lesions smaller than 10 mm.

On follow-up, patients underwent ultrasound only or ultrasound plus subsequent surgery. Follow-up ranged from 0 to 84 months (median, 3 months).

Of the 101 patients in the study, 17 underwent surgery immediately after ultrasound, 8 underwent surgery after follow-up ultrasound, and 76 underwent no surgery after ultrasound follow-up.

Overall, 9 of the lesions were malignant (8.9%), and those patients all underwent surgery. No hyperechoic lesions were malignant. However, 17.7% of the hypoechoic lesions were malignant (95% confidence interval [CI], 7.2% to 28.1%), as were 36.0% of lesions treated with surgery (95% CI, 17.2% to 54.8%).

Pathology results indicated that the most common type of malignant lesion was seminoma, and the most common benign tumor, accounting for nearly 50% of cases, was Leydig cell.

The strongest independent factors predicting malignancy were lesion size and testicular microlithiasis (β = 0.827, 2.627; P < .05).

For patients who underwent surgery, ultrasound surveillance had a sensitivity for diagnosing malignancy of 88.9% and a specificity of 87.5%.

"Our results show that the majority of small testicular lesions are likely benign," Dr. Li said. "Ultrasound surveillance may be an appropriate means of risk-stratifying patients with small testicular lesions."

These findings support the approach usually taken for smaller testicular lesions, according to oncologist Bruce Roth, MD, professor of medicine in the division of oncology at Washington University School of Medicine in St. Louis, Missouri.

"Overall, the tendency in testicular cancer has been toward more nonintervention and surveillance, so it would be a logical extension to suggest that lesions under 10 mm should be followed with ultrasound," said Dr. Roth.

But Dr. Roth, an official with the American Society of Clinical Oncology, noted that such patients might not be easily identified because they don't usually have symptoms.

"I'm not sure how pertinent this is for a diagnosis of cancer because we don't usually see patients who have 5 mm lesions. In general, they are not symptomatic; those likely aren't patients who are going to have, for instance, testicular pain or firmness."

"A lesion of that size would typically only be picked up almost incidentally if the patient is worked up for another reason, either for trauma to the testicle or something else."

He added that the study doesn't explain why some patients underwent surgery and others didn't.

"It's worrisome that among the lesions that did go to surgery, 36% had a malignancy," Dr. Roth said. "It's not a random assignment here — there had to be something else about those cases that told surgeons to go look for a malignancy, as opposed to ones that were just followed with ultrasound."

Dr. Li and Dr. Roth have disclosed no relevant financial relationships.

American Institute of Ultrasound in Medicine (AIUM) 2012 Annual Convention: Abstract 1240358. Presented March 31, 2012.