Case Files Surgery, (LANGE Case Files) 4th Ed.

SECTION II. Clinical Cases

CASE 5

A 63-year-old man complains of a 6-month history of difficulty voiding and feeling as though he cannot empty his bladder completely. After voiding, he often feels as though he needs to urinate again. He denies a urethral discharge. He has mild hypertension and takes hydrochlorothiazide. His only other medication is ampicillin prescribed for two urinary tract infections during the past year. On examination, his blood pressure is 130/84 mm Hg and his pulse rate 80 beats/min; he is afebrile. Findings from examinations of the heart and lungs are normal, and the abdomen reveals no masses.

Images What is the most likely diagnosis?

Images What is the best initial therapy for this patient?

ANSWERS TO CASE 5: Benign Prostatic Hyperplasia

Summary: A 63-year-old hypertensive man complains of a 6-month history of difficulty voiding and feeling as though he cannot empty his bladder completely. He has experienced two episodes of cystitis. He denies dysuria or urgency and does not have a urethral discharge.

• Most likely diagnosis: Lower urinary tract symptoms (LUTS), which in men occur most commonly as the result of benign prostatic hyperplasia (BPH).

• Best initial therapy: Initial therapy with α-blocking agent or 5-alpha reductase inhibitors is appropriate, and transurethral prostatectomy (TURP) if the patient fails to improve with medical management.

ANALYSIS

Objectives

1. Learn the clinical presentation of BPH.

2. Learn the differential diagnosis for urinary outlet obstruction in males and when a biopsy is appropriate.

Considerations

The prostate gland is the male reproductive organ positioned at the base of the bladder that completely encircles the urethra as it exits the bladder and before it becomes part of the penile urethra. The physiologic function of the prostate is to produce the ejaculate, which serves as a vehicle for spermatozoa. As the man ages, the prostate increases in size. This increase in size can have consequences because the human prostate is the only mammalian prostate with a capsule. The capsule restricts expansion of the prostate gland as BPH progresses. The bladder neck and prostatic urethra become compromised in their function, leading to a condition known as bladder outlet obstruction.

Symptoms of BPH, known as prostatism, include irritative and obstructive symptoms. They can include frequent urination of small amounts, a feeling of incomplete voiding with subsequent attempts to urinate to achieve the feeling of bladder emptying, slow urinary flow, voiding at night after sleep (nocturia), hesitancy at the beginning of urinary flow, and, in its extreme form, complete urinary retention. Several international organizations have recommended the use of formal symptom scoring systems such as the International Prostate Symptom Score (IPSS) or American Urological Association (AUA) Symptom Score to quantify the severity of symptoms and objectively follow patients’ responses to treatment.

Several conditions that produce similar symptoms mimic BPH. Urethral stricture disease (a narrowing of the urethra with scarring), urinary tract infection, including infection of the prostate (prostatitis), prostate cancer, and neurologic conditions affecting the control and strength of bladder contraction all mimic and may be indistinguishable from BPH. When there is nodularity or an elevation in the prostate-specific antigen (PSA), biopsy of the prostate is generally indicated.

APPROACH TO: Urinary Outlet Obstruction

DEFINITIONS

MICTURITION: The physiologic act of voiding. This involves contraction of the detrusor (bladder muscle) followed by relaxation of the bladder neck and other urinary sphincters to allow unrestricted, complete emptying of the bladder in a single setting.

DIGITAL RECTAL EXAMINATION (DRE): The prostate is palpated with a gloved examining finger inserted into the rectum. The normal prostate has the “feel” of the thenar eminence of the thumb (Figure 5–1).

Images

Figure 5–1. A digital rectal examination is performed to detect nodularity in the prostate gland.

PROSTATE-SPECIFIC ANTIGEN: A blood protein normally produced by the prostate. PSA is specific to the prostate but not to a particular condition of the prostate because age, size, infection, and cancer are among the several reasons why PSA values can be elevated.

URODYNAMICS: Testing performed on the function of the bladder in both its filling and emptying phases, which may be as simple as voiding into a specially developed toilet to measure the voiding flow rate to as complicated as the placement of a catheter into the urinary bladder to measure pressures and volumes during filling and emptying.

α-BLOCKERS: These agents include alfuzosin, doxazosin, tamsulosin, terazosin, and silodosin. α-Blockers cause smooth muscle relaxation and can increase the diameter of the bladder neck and prostatic urethra. This may be used together with 5-alpha reductase inhibitors.

5-ALPHA-REDUCTASE INHIBITORS: Dihydrotestosterone (DHT) is converted from testosterone, and DHT levels remain high within the prostate. DHT is a potent stimulator in BPH progression. 5-Alpha reductase inhibitors target the conversion of testosterone to DHT, and thus produce shrinkage of the prostate gland.

CLINICAL APPROACH

When faced with the vague symptomatology of prostatism, the initial duty of the physician is to exclude other etiologies because the treatment would differ. This exclusion process begins with obtaining a history and looking for associated signs and symptoms of other disease processes. A review of systems should entail a search for neurologic abnormalities. A urinalysis is the cornerstone of laboratory testing to exclude the presence of a urinary tract infection or microscopic hematuria that might indicate a bladder tumor. PSA blood testing should be performed as well as determination of the serum creatinine level to rule out severe prostatism with renal compromise. A DRE not only characterizes the size of the prostate but also is performed to exclude the presence of a palpable nodule suggestive of prostate cancer (see Figure 5–1). Even the best history and physical and laboratory testing may not discriminate between bladder outlet obstruction secondary to BPH and a urethral stricture because both of these pathologic entities are secondary to restriction of the urethra. If a patient requires urodynamic testing in cases in which the diagnosis is not clear, consultation with a urologist is generally helpful. Making matters more difficult, prostatism may coexist with a urinary tract infection and/or a neurologic disease such as Parkinson disease. Evidence of renal compromise, an elevated serum creatinine value and/or urinary retention, multiple small voids with incomplete emptying, and/or a palpable bladder on physical examination call for urgent urologic intervention.

Once the correct diagnosis of BPH is made, initial treatment is often medical. Two classes of medication are available for the management of prostatism. The first class is α1-antagonist agents, which cause relaxation of the prostate smooth muscle, thereby increasing the functional diameter of the urethra (common agents include terazosin, doxazosin, and tamsulosin). Another class of medication used in the management of prostatism causes a reduction in prostate size by blocking a metabolite of testosterone (5-alpha reductase inhibitor, most commonly used is finasteride), thus leading to the involution of prostate glandular tissue and shrinkage of the overall prostate size. When medical therapy fails, surgical intervention, which serves to destroy prostate obstructing tissue, is used. The standard operative procedure is known as transurethral resection of the prostate, or TURP. This procedure is carried out transurethrally using a specially developed scope that has attached to it a cutting element with water irrigation. “Chips” of the prostate are carved out from within the prostate urethra and removed via the scope. Alternative methods to destroy prostate tissue include the use of a laser, radiofrequency waves, or microwaves. Rarely, the prostate enlarges to such a size that open surgical removal known as a suprapubic prostatectomy is required. Regardless of the method of therapy chosen to manage BPH, the patient needs to be monitored thereafter for response to therapy because residual glandular tissue will continue to grow.

COMPREHENSION QUESTIONS

5.1 A 57-year-old asymptomatic man is noted to have a prostate that is normal in shape and size on rectal examination. His PSA level is 38 ng/mL (normal, 2.5 ng/mL). Which of the following is the best next step for this patient?

A. Observation

B. Transrectal ultrasound examination with a prostate biopsy

C. Repeated PSA testing in 6 months

D. CT scan of the abdomen and pelvis

E. Initiation of finasteride therapy

5.2 A 72-year-old man has a lower abdominal mass and constantly dribbles urine. Which of the following is the best next step in management?

A. CT scan of the pelvis

B. Enema

C. Placement of a Foley catheter

D. Referral to a general surgeon and a neurologist

E. Pelvic ultrasound

5.3 A 58-year-old commercial airline pilot has confirmed prostatism. He is being treated by a doctor but seeks treatment in the emergency department for dizziness, which precludes his flying. Which of the following is the most likely problem?

A. Drug side effect

B. Unrecognized Parkinson disease

C. Undiagnosed metastatic prostate cancer

D. Silent renal failure

E. Urinary tract infection

5.4 A 42-year-old man requests prostate “testing” because his father has recently been given a diagnosis of prostate cancer. You perform a DRE, which reveals a normal-sized, smooth prostate gland. A PSA test is then performed and is run immediately because the patient insists on knowing the results before leaving the office. The PSA result is 3.2 ng/mL (normal, 2.5 ng/mL). Which of the following is the best next step?

A. CT scan of the abdomen and pelvis for a workup for prostatic cancer.

B. Sonographically directed prostate biopsy.

C. Repeated PSA test.

D. Prostatectomy with pelvic lymphadenectomy.

E. Reassure the patient that he is fine and schedule for follow-up in 1 year.

ANSWERS

5.1 B. Even though elevation in PSA is not specific for prostate cancer, the substantially elevated PSA value in this patient is concerning and would require a prostate biopsy to assess for prostate cancer. Transrectal sonography is performed to help identify abnormal areas within the prostate and determine the best locations for the biopsy. CT scan is not indicated because it lacks the resolution to identify small lesions in the prostate.

5.2 C. Overflow incontinence occurs when the urinary bladder is filled to capacity. As the pressure rises, with standing and coughing, a small amount of urine leaks out of the bladder through the restricted bladder outlet in a dribbling fashion. A small amount of urine is seen to squirt from the penis as the Valsalva maneuver pushes on the massively distended bladder. Immediate urinary drainage and hospitalization are in order. While a pelvic ultrasound could be obtained to verify the presence of an overdistended bladder, this patient’s problem should be diagnosed on the basis of his history and physical examination.

5.3 A. The α1-antagonist class of medications, originally developed for blood pressure control, relaxes the smooth muscle within the arterial wall and can cause a decrease in blood pressure leading to dizziness and/or syncope (fainting). Patients must be warned of this side effect. Titration and nighttime dosing are often required to minimize the disability associated with this treatment.

5.4 C. Mild elevations of the PSA value may be seen immediately after a DRE. The best course in this case is to repeat the PSA test several days to 1 week later. The PSA is most useful for patients who have had treatment for prostate cancer to detect recurrence. PSA screening has not been shown definitively to reduce mortality due to prostate cancer. Nevertheless, many practitioners advocate screening after the age of 50.

CLINICAL PEARLS

Images Patients with symptoms suggestive of BPH should undergo a renal function test (creatinine), a PSA test, urinalysis, and a DRE.

Images The IPSS can characterize voiding symptoms based on a patient’s report of incomplete emptying, frequency, intermittency, urgency, weak stream, straining, and nocturia.

Images Although there is no physiologic relationship between BPH and prostate malignancy, the age of onset of these two clinical entities overlaps.

Images Distinguishing characteristics of prostate cancer include a firm, hard, and/or misshapen prostate gland on examination and/or an elevated or elevating PSA value. Both BPH and prostate malignancy can coexist in the same patient.

Images The diagnosis of prostate cancer is made with transrectal biopsy of the prostate.

REFERENCES

Djavan B, Eckersberger E, Finkelstein J, et al. Benign prostatic hyperplasia: current clinical practice. Prim Care. 2010;37:583-597.

Djavan B, Margreiter M, Dianat SS. An algorithm for the medical management in male lower urinary tract symptoms. Curr Opin Urol. 2011;21:5-12.

Nickel JC, Mendez-Probst CE, Whelan TF, et al. 2010 update: guidelines for the management of benign prostatic hyperplasia. Can Urol Assoc J. 2010;4:310-316.