Tuberculous prostatic abscess following intravesical bacillus Calmette-Guérin immunotherapy.

To the Editor: A 57-year-old man was diagnosed with bladder cancer and underwent bladder tumor transurethral resection to treat a high-grade T1 urothlial carcinoma. Intravesical bacillus Calmette-Guérin (BCG) (BCG for Therapeutic Use, CDIBP, China) immunotherapy was performed once per week for 6 weeks at a concentration of 120 mg in 50 mL saline. The patient had no history of tuberculosis. After 6 weeks of treatment, the patient complained of perineal discomfort. A digital rectal examination (DRE) showed tenderness, thus resulting in suspicion of infection in the left lobe of the prostate. Microscopic urinalysis showed few red blood cells. The level of total prostate-specific antigen (PSA) was 2.61 ng/mL, and the free PSA was 0.23 ng/mL. A magnetic resonance (MR) scan was performed to evaluate prostate infection and revealed an approximately 2.1 × 1.2 cm hypo-intense lesion on T2-weighted imaging (T2WI) and hyper-intensity on diffusion-weighted imaging in the peripheral zone of the left prostate gland [Figure 1A and 1B]. For differential diagnosis of the prostatic hypo-intense lesion on T2WI, a prostate biopsy was performed. Subsequent histology showed granulomatous prostatitis [Figure 1C] positive for tuberculosis according to polymerase chain reaction. There was no evidence of tuberculosis elsewhere. On the basis of these findings, tuberculous prostatic abscess was confirmed. The patient was treated with a 9-month anti-tuberculous regime of isoniazid (300 mg/day), rifampicin (450 mg/day), and ethambutol (750 mg/day). The symptoms were relieved after 1 month of anti-tuberculous therapy. After completion of the 9-month regimen of anti-tuberculous therapy, a follow-up MR scan was performed, which indicated disappearance of the prostatic abscess. The most recent cystoscopy showed no evidence of tumor recurrence and no inflammation of the prostate.

Figure 1

Pelvic magnetic resonance imaging showing a prostatic lesion in the left lobe (A and B). Histopathology showing granulomatous inflammation in the left lobe of the prostate (H&E staining, original magnification ×200; C).

Adjuvant intra-vesical immunotherapy with BCG is considered the first-line therapy in patients with high-risk non-muscle invasive bladder cancer after surgery. This therapy is generally safe but has rare complications of tuberculous infection in the prostate, which can occur via hematogenous spreading and through direct extension of the infection.[ The direct extension of tuberculosis from the bladder may cause prostatic abscess.[ Lamm et al[ reviewed 2602 cases of bladder cancer treated with intra-vesical BCG immunotherapy and found that localized BCG infection is a rare complication. The rate of granulomatous prostatitis is approximately 0.9%, but granulomatous prostatitis leading to a tubercular abscess after BCG treatment is rarely reported and maybe an extremely rare complication.[ If the diagnosis and treatment of prostate abscess are delayed, the condition can progress to sepsis. Therefore, proper diagnosis and treatment are crucial. Diagnosis of a prostate abscess is performed with DRE, transrectal ultrasonography or MR scan and biopsy.[ If DRE shows abnormalities in patients, a prostate biopsy is necessary for the differential diagnosis of prostate cancer. Transurethral or transperineal drainage with 9 to 12 months of anti-tubercular treatment has been used as a tubercular prostatic abscess treatment modality. However, some patients have been successfully treated with only anti-tubercular drugs.

This case illustrates that when BCG immunotherapy for bladder cancer is performed, tuberculous prostatitis with abscess can develop. This outcome indicates that conservative treatment with anti-tubercular drugs may be useful in treating tuberculous prostatic abscess, and surgical drainage is not always necessary.

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Conflicts of interest

None.