What is the differential diagnosis for a male patient presenting with frank hematuria (visible blood in the urine) only during erections?

Differential Diagnosis for Frank Hematuria Only with Erections

Frank hematuria occurring exclusively during erections is an extremely rare presentation that most likely originates from the seminal tract (prostate, seminal vesicles, or ejaculatory ducts) rather than the urinary tract proper, though this requires urgent urologic evaluation to exclude malignancy given the 30-40% cancer risk associated with gross hematuria. 1

Primary Differential Considerations

Seminal Tract Pathology (Most Likely Source)

The timing—hematuria only with erections—strongly suggests bleeding from structures involved in the ejaculatory pathway rather than the bladder or kidneys:

• Seminal vesicle abnormalities including cysts, calculi, or hemorrhage within the seminal vesicles can cause bleeding that manifests during erection due to increased vascular engorgement 1
• Ejaculatory duct obstruction or calculi may cause bleeding that becomes apparent only when these structures are engorged during erection 1
• Prostatic pathology including prostatitis, prostatic cysts, or prostatic calcifications can bleed during the vascular changes of erection 1
• Cowper gland masses or abnormalities may present with bleeding during sexual arousal 1

Vascular Causes

• Arteriovenous malformations or vascular anomalies of the prostate or seminal tract that become symptomatic only with the hemodynamic changes of erection 1
• Internal pudendal artery abnormalities that may bleed during erection-related vascular engorgement 1

Urethral and Penile Causes

• Urethral hemangiomas or vascular lesions that bleed with increased blood flow during erection 1
• Posterior urethral pathology near the verumontanum that becomes symptomatic during erection 1

Malignant Causes (Must Be Excluded)

Despite the unusual presentation, malignancy must be rigorously excluded:

• Bladder cancer can present with gross hematuria and carries a 30-40% probability in patients with visible blood 1
• Prostate cancer particularly if there is prostatic involvement causing bleeding during vascular engorgement 1
• Urethral carcinoma though rare, can present with bleeding during erection 1

Critical Diagnostic Approach

Immediate Evaluation Required

All patients with gross hematuria require urgent and complete urologic evaluation with cystoscopy and upper tract imaging, regardless of whether bleeding is self-limited or a benign cause is suspected. 1

Initial Workup

• Confirm true hematuria with microscopic urinalysis showing ≥3 RBCs per high-power field, not contamination from a sexual partner 1, 2
• Complete urinalysis with microscopy to assess for dysmorphic RBCs, casts, and proteinuria to exclude glomerular causes 2, 3
• Urine culture to exclude infection, though infection would not typically cause hematuria only with erections 2, 3
• Serum creatinine to assess renal function 2, 3

Specialized Imaging

• Transrectal ultrasound (TRUS) is the first-line imaging modality for evaluating the prostate and seminal tract, demonstrating abnormalities in 82-95% of men with seminal tract bleeding 1
• Pelvic MRI is recommended when TRUS is negative or inconclusive, as it provides superior visualization of the seminal vesicles, ejaculatory ducts, and prostatic anatomy 1
• CT urography (multiphasic) is mandatory to evaluate the upper urinary tract for malignancy, stones, and other pathology 1, 2

Mandatory Endoscopic Evaluation

• Flexible cystoscopy is mandatory for all patients with gross hematuria to visualize the bladder mucosa, urethra, and ureteral orifices 1, 2
• Consideration of seminal vesiculoscopy if TRUS and MRI suggest seminal tract pathology, as this has 74.5% diagnostic accuracy for detecting calculi and strictures 1

Vascular Assessment

• Pelvic angiography should be reserved for cases where clinical, laboratory, and noninvasive imaging have not revealed an etiology, particularly if bleeding is intractable 1

Common Pitfalls to Avoid

• Never attribute gross hematuria to benign causes without complete evaluation—even unusual presentations like erection-associated bleeding carry significant malignancy risk 1
• Do not assume this is hematospermia—confirm the blood is in urine, not ejaculate, and that it's not contamination from a partner 1
• Do not defer evaluation due to the unusual presentation—the 30-40% malignancy risk with gross hematuria applies regardless of timing 1
• Anticoagulation or antiplatelet therapy does not explain hematuria—these medications may unmask underlying pathology but evaluation must proceed 1, 2

Age-Specific Considerations

• Men ≥40 years require prostate-specific antigen (PSA) screening in addition to the complete hematuria workup 1
• Men ≥60 years are automatically high-risk and require the most aggressive evaluation 2

Follow-Up Protocol

If initial evaluation is negative but hematuria recurs:

• Repeat urinalysis at 6,12,24, and 36 months with blood pressure monitoring 2, 3
• Immediate re-evaluation if gross hematuria recurs, degree of hematuria increases, or new urologic symptoms develop 2, 3
• Consider repeat complete evaluation within 3-5 years for persistent or recurrent symptoms in high-risk patients 2