A prostate lesion is a term for any abnormal area of tissue found within the prostate gland. The word “lesion” is a broad descriptor used by medical professionals and is not a final diagnosis. Hearing this term can be concerning, but it marks the first step in an investigative process to understand the specific nature of the abnormal cells.
Identifying Prostate Lesions
Identifying a prostate lesion often begins with routine screening. An elevated Prostate-Specific Antigen (PSA) level in a blood test or an abnormal finding during a Digital Rectal Exam (DRE) can indicate a need for further investigation. These initial results signal that a closer look at the prostate is warranted.
When further investigation is needed, the primary tool used is a multiparametric Magnetic Resonance Imaging (mpMRI) scan. This advanced imaging technique provides detailed pictures of the prostate’s soft tissues, allowing radiologists to see areas that appear different from normal tissue. The mpMRI is highly effective at detecting and localizing suspicious areas within the gland.
Radiologists use the Prostate Imaging Reporting and Data System (PI-RADS) to classify any lesions they find. This system uses a 5-point scale to report the likelihood that a lesion is a clinically significant cancer. A PI-RADS 1 score indicates a very low likelihood, while a PI-RADS 5 score signifies a very high probability.
Types of Prostate Lesions
After a lesion is identified, a primary concern is determining its nature, as not all prostate lesions are cancerous. Many are benign, meaning they are non-cancerous and do not spread. Common benign conditions that can appear as lesions include Benign Prostatic Hyperplasia (BPH), a non-cancerous enlargement of the prostate, and prostatitis, which is inflammation of the gland.
Some lesions are categorized as atypical or pre-cancerous, where cells appear abnormal under a microscope but are not yet cancer. Two common findings in this category are High-Grade Prostatic Intraepithelial Neoplasia (HGPIN) and Atypical Small Acinar Proliferation (ASAP). HGPIN describes architecturally normal prostate glands lined with atypical cells, while ASAP refers to a small focus of glands that are suspicious for cancer. Both are considered risk factors for developing prostate cancer and require closer monitoring.
Some prostate lesions are malignant, meaning they are cancerous. The most common type of prostate cancer is adenocarcinoma, which develops from the gland cells of the prostate. If a lesion is found to be cancerous, it has the potential to grow and spread to other parts of the body.
The Diagnostic Process After Detection
Once a suspicious lesion is identified on an MRI, particularly one with a higher PI-RADS score, the next step is a prostate biopsy. A biopsy is a procedure to remove small samples of prostate tissue for a pathologist to examine under a microscope. This examination provides a definitive diagnosis, confirming the presence and characteristics of any abnormal cells.
Modern biopsy techniques have become highly precise. An MRI-fusion biopsy, for example, combines the detailed images from the pre-biopsy mpMRI with live ultrasound images. This technology allows the urologist to guide the biopsy needle directly to the suspicious lesion, ensuring that the most informative tissue samples are collected. This targeted approach increases the accuracy of detecting significant cancer.
If cancer is detected, the pathologist will assign a Gleason score. This grading system evaluates the aggressiveness of the cancer based on how abnormal the cell patterns appear. The pathologist identifies the two most common cancer patterns and assigns each a grade from 3 to 5. These two grades are added together to produce a Gleason score from 6 to 10. A lower score indicates a less aggressive cancer, while a higher score signifies a more aggressive cancer.
Management and Monitoring
The final diagnosis from the biopsy and the Gleason score will guide the management plan. Not all findings require immediate aggressive intervention.
For benign findings like BPH or prostatitis, the focus is on managing the underlying condition. This may involve medications to relieve urinary symptoms or antibiotics to treat inflammation. In many cases, simple monitoring over time is all that is needed.
For a diagnosis of low-risk prostate cancer, a primary management strategy is active surveillance. This approach involves carefully monitoring the cancer with:
- Regular PSA tests
- Periodic DREs
- Follow-up mpMRI scans
- Potential repeat biopsies to check for any changes
Active surveillance avoids or delays the side effects of treatment while ensuring the cancer is addressed if it shows signs of progressing.
If the cancer is determined to be of a higher risk or more aggressive grade, active treatment options will be discussed with a specialist. These treatments are aimed at curing the cancer and may include surgery to remove the prostate (prostatectomy) or various forms of radiation therapy. The choice of treatment depends on many factors, including the cancer’s stage and grade, as well as the patient’s age and personal preferences.