Grades of Prostatomegaly in BPH
Prostatomegaly in BPH is most commonly classified by prostate size thresholds that guide surgical approach: small prostates (≤30g) are candidates for TUIP, moderate-sized glands can be managed with standard TURP, and large prostates (>60g) typically require simple prostatectomy or advanced transurethral techniques.
Size-Based Classification for Surgical Planning
The most clinically relevant grading system for prostatomegaly relates directly to treatment selection:
Small Prostates (≤30g)
- TUIP is the preferred surgical option for prostates ≤30g, offering lower rates of retrograde ejaculation (18.2% vs 65.4%) and blood transfusion (0.4% vs 8.6%) compared to TURP 1
- These patients may also be candidates for medical therapy with alpha-blockers alone, as 5-alpha reductase inhibitors are ineffective without demonstrable prostatic enlargement 1
Moderate-Sized Prostates (30-60g)
- Standard monopolar or bipolar TURP remains the gold standard for this size range 1
- Alternative options include bipolar TUVP and PVP using 120W or 180W platforms 1
- Digital rectal examination typically underestimates true prostate size in this range, so ultrasound measurement is more reliable 1
Large Prostates (>60g)
- Simple prostatectomy (open, laparoscopic, or robotic-assisted) should be considered for large prostates, though the Panel acknowledges that experienced surgeons may successfully use bipolar TURP or HoLEP for glands >60g 1
- Bipolar TURP has advantages over monopolar for larger glands due to reduced risk of TUR syndrome and hyponatremia, allowing longer resection times 1
Alternative Classification Systems
MRI-Based Anatomic Classification
A more detailed classification system exists based on enlargement location 2:
- Type 0: Prostate ≤25 cm³ with minimal zonal enlargement
- Type 1: Bilateral transition zone enlargement
- Type 2: Retrourethral enlargement
- Type 3: Combined bilateral TZ and retrourethral enlargement
- Type 4: Pedunculated enlargement
- Type 5: Pedunculated with bilateral TZ and/or retrourethral enlargement
- Type 6: Subtrigonal or ectopic enlargement
- Type 7: Other combinations
This anatomic classification helps predict symptoms and optimal treatment approaches, though it requires MRI imaging and is not routinely used in clinical practice 2.
Functional Staging System
A clinical staging system based on symptoms and obstruction has been proposed 3:
- Stage I: No bothersome symptoms (QOL <3) and no significant obstruction (PVR ≤100ml) - observation appropriate
- Stage II: Bothersome symptoms (QOL ≥3) but no significant obstruction - medical therapy first-line
- Stage III: Significant obstruction (PVR >100ml) regardless of symptoms - TURP recommended
- Stage IV: Complications of BPH present - TURP strongly recommended
In this staging system, 91% of patients improved to Stage I post-TURP, validating its utility for treatment planning 3.
Clinical Implications
The key clinical decision point is whether the prostate is enlarged enough to benefit from 5-alpha reductase inhibitors (finasteride or dutasteride), which are only effective in patients with demonstrable prostatic enlargement 1. Men with higher serum PSA levels (a proxy for prostate size) have higher risk of prostate growth, symptom deterioration, acute urinary retention, and need for BPH-related surgery 1.
Important Caveats
- DRE consistently underestimates true prostate size; if the prostate feels large on DRE, it is usually confirmed enlarged by ultrasound 1
- Prostate volume measurement becomes critical when considering 5-alpha reductase inhibitors, as these medications reduce risk of acute urinary retention and BPH-related surgery only in men with enlarged prostates 1
- The presence of intravesical prostatic protrusion (IPP) on ultrasound correlates with obstruction severity and can guide treatment decisions 3