Chronic bacterial prostatitis leading to intrascrotal abscess after transperineal prostate biopsy

Abstract

Transperineal biopsy is becoming more commonly used, driven by improved detection rates, better complication profile and increasing application of prostate MRI leading to guided biopsy. However, it can still lead to complications such as urinary retention, postoperative pain and erectile dysfunction. There is also a potential for adverse events such as severe infection, abscess and fistula. This article describes a case of an intrascrotal abscess post-transperineal biopsy, which required an orchidectomy.

Background

There are two common methods for performing prostate biopsy—transrectal (TR) and transperineal (TP). TP biopsy is becoming more commonly used because of lower rates of complications such as sepsis and bleeding when compared with a TR approach.^1–4 Most importantly, it has better prostate cancer detection rates, especially for anteroapical cancers.⁵ However, TP biopsy has higher rates of acute urinary retention, intraoperative pain and erectile dysfunction.^{1 4} Adverse events, such as severe infection, abscess and fistula, are also possible. This case describes such a complication of a scrotal abscess post-TP biopsy requiring simple orchidectomy.

Case presentation

A man in his early fifties had symptoms of dysuria, urinary frequency and urgency. He presented to his general practitioner (GP), and was found to have an exquisitely tender prostate on digital rectal examination. His serial urine cultures separately grew Enterococcus faecalis and Escherichia coli, and his prostate-specific antigen (PSA) was elevated at 22.6 µg/L. His GP prescribed him with repeated courses of oral antibiotics; either trimethoprim or amoxicillin–clavulanate, where his symptoms would recur in between courses. This was ongoing for a period of 2 months. His PSA also did not reduce below 9 µg/L, for which he was referred to a urologist. The urologist treated him with further courses of oral amoxicillin–clavulanate, as the same bacteria were isolated from subsequent urine cultures, which remained sensitive. His PSA repeated 2 months later stayed elevated, and an MRI of the prostate was done, which showed a 9 mm Prostate Imaging-Reporting and Data System (PIRADS)4 lesion in the right peripheral zone from the mid gland to apex, without any extracapsular, seminal vesicle extension or lymphadenopathy. This led to a TP biopsy 5 weeks later, which was performed without immediate complications.

Five days after his prostate biopsy, he started developing right testicular pain and swelling. His GP organised a scrotal ultrasound, which showed epididymitis and an epididymal head cyst. He was commenced on oral ciprofloxacin.

He then presented to a peripheral hospital 10 days later, with increasing pain, fevers, nausea and lethargy. His white cell count (WCC) was 12.7×10⁹/L and the C reactive protein (CRP) was 359 mg/L. His urine culture and sexually transmitted infection screen were negative. An ultrasound was performed, which showed that the right epididymis was enlarged with increased blood flow on the doppler. This was associated with a 6 mm fluid-filled mass in the tail of the epididymis, consistent with an abscess. He was admitted and treated with 5 days of intravenous Ciprofloxacin 400 mg three times a day. An ultrasound repeated prior to discharge showed features of ongoing epididymo-orchitis, but with resolution of the abscess. He was discharged on a further 6 weeks course of oral ciprofloxacin.

Eleven days later, the testicular pain and swelling worsened, and he presented our hospital. He was afebrile and had no signs of systemic infection. The right hemiscrotum was erythematous, swollen and tender, with a fluctuant intrascrotal mass that was adherent to the superior pole of the testis (figure 1).

Figure 1.

Right swollen, erythematous and tender scrotum, with a fluctuant intrascrotal mass.

Investigations

He had a WCC of 8.7×10⁹/L and CRP of 31 mg/L. A repeat ultrasound again showed a right enlarged and hyperaemic epididymis, and a 32 mm heterogeneous collection superior to the testis, in keeping with a recurring abscess. The right testis had a heterogeneous appearance with multiple focal non-vascular hypoechoic areas. There was no bacterial growth on urine culture (figures 2 and 3).

Figure 2.

Longitudinal ultrasound view of enlarged right epididymis with heterogeneous collection superior to the right testis.

Figure 3.

Abscess with surrounding rim of vascularity in right testis.

Treatment

He was initially started on intravenous amoxicillin–clavulanate and gentamicin. As the infection was not resolving with antibiotic therapy, our patient went to theatre for a right scrotal exploration. An incision was made in the scrotum over the mass, revealing a 4 cm abscess cavity extending deep into the superior pole of the testis. The cavity was drained and washed out with normal saline. Necrotic tissue around the testes was debrided. The testicular capsule was found to be ruptured, with seminiferous tubules spilling in the haemiscrotum. A simple orchidectomy was performed, and a corrugated drain was then placed through the trans-scrotal incision (figure 4).

Figure 4.

Right perforated testes after wash-out and debridement.

Our patient had an uncomplicated postoperative recovery. The drain tube was removed on day 4 postoperatively. He remained well and not septic. After 3 days of intravenous amoxicillin+clavulanate and gentamicin, he was discharged with a 2 weeks course of oral amoxicillin-clavulanate.

Outcome and follow-up

Our patient was well at 2 weeks review, with no signs of residual infection. Intraoperative swabs of the pus showed polymorphs and an unidentified gram-negative bacillus that failed to grow on culture.

He followed up with urologists in the previous hospital for the biopsy results, which came back as a Gleason 3+4 prostate adenocarcinoma, involving 5 of 15 cores. There were also acute on chronic inflammatory cell infiltrates seen in a few of the cores. He had negative staging CT and bone scan. He subsequently had an open radical prostatectomy. The final histopathology concurred with the biopsy, with Gleason 3+4 prostate adenocarcinoma, pT2 without extraprostatic extension or seminal vesicle invasion.

Discussion

Abscess is an extremely rare complication following a prostate biopsy, and to our knowledge, this is the first case of such description in the published literature. Our patient’s intrascrotal abscess postprostate biopsy was likely attributed to the 6 months history of recurrent prostatitis. The prostate was most likely chronically infected or colonised with E. coli or E. faecalis, which were isolated on past urine cultures. Given the patient’s ongoing symptoms, these infections were inadequately treated with the repeated courses of oral antibiotics. The ensuing prostate biopsy allowed the retrograde spread of infection through the vas deferens and seeding of infection into the epididymis.

TR prostate biopsies have been performed since 1963 with the introduction of TR ultrasonographic evaluation of prostate.⁶ However, there can be complications such as sepsis, rectal bleeding, haematuria, haematospermia and acute urinary retention.⁷ Generally, rectal bleeding and haematuria are self-limited, but more severe complications such as infections and severe bleeding might require readmissions.

In contrast, TP biopsy is shown to have lesser complication rates. A meta-analysis reports TP biopsy to have decreased risk of infections, with a relative risk of 0.26 (95% CI 0.14 to 0.48).⁴ Xiang et al also recommended that patients who are prone to severe infections, including immunocompromised, diabetics and those with long term urinary catheters, to undergo TP biopsy to avoid severe sepsis postoprative. Multiple other studies reported similar findings. Skouteris et al found lower rates of UTI post-TP biopsy compared with TR biopsies, 0.79%–4.2%, respectively.³ Lo et al found a 4% rate of infection post TR requiring at least a 1 week admission for IV antibiotics, as compared with zero patients from the TP group.² Bhatt et al assessed patient-reported experiences after both TP and TR biopsies, and found a 12% lower incidence of postoperative presentations for infective symptoms or haematuria, after TP biopsy as compared with TR.¹ The risk of infection was also found to be higher with the number of biopsies taken, 14.8% for patients with 13 or more cores, compared with 2.9% with 12 or less cores.

In terms of other side effects, Bhatt et al found that urinary retention was higher in TP biopsy, 16.7% compared with 5.7% in TR.¹ Skouteris et al found TP biopsies to have higher rates of urinary retention 7.9%, with no retention in the TR biopsy group.³ TP biopsy under LA was shown to have higher incidences of intraoperative pain with a relative risk of 1.83 (95% CI 1.27 to 2.65), as compared with TR.⁴ In terms of postoperative pain, Bhatt et al reported that TR biopsies under LA have higher incidences of postoperative pain compared with TP biopsy under GA, 86% vs 61%.¹ TP biopsies are associated with higher rates of erectile dysfunction as well, but lesser rates of rectal bleeding, with a relative risk of 0.02 (95% CI 0.01 to 0.06).^{1 4}

Cases of fistulas and mortality have also been described post-TR biopsies.^{8 9} There was a reported TP biopsy complication of a recto-peritoneal fistula in an 84-year-old man.¹⁰ The patient represented 5 days post-TP biopsy, with severe abdominal pain and peritonism, and a CT showed intra-abdominal abscess with retroperitoneal free gas. He was treated with an ileostomy. There are no other reports for severe adverse events post-TP biopsies. To our knowledge, this is the first case of intrascrotal abscess following TP biopsy of the prostate in the published literature.

Patient’s perspective.

‘Approximately 5 days after returning from a family holiday in Thailand in mid-May 2019, I started experiencing discomfort when urinating. Tests revealed I had an aggressive e-coli type of infection and a high PSA count. A CT scan showed no other problems.

At the advice of my GP and subsequently a private Urologist, I began multiple courses of antibiotics which relieved my symptoms during their use, but discomfort returned quickly after the completion of each course. The long use of these antibiotics became frustrating and only managed to get my PSA down to about 9 from 20 something within the period of May to October. At the end of October, we decided to have an MRI, which revealed a growth on my prostate. Subsequently a biopsy was performed at the beginning of December without a subsequent course of antibiotics… Although I kept busy and tried not to let it enter my thoughts too much, it was a slightly nervous wait.

Approximately a week or so after the biopsy, I started experiencing discomfort in my right testicle. At first, I thought it was a result of possibly squashing it somewhere during work, but in a few days, it escalated into severe pain and swelling. I went to a peripheral hospital and was treated with intravenous antibiotics for about 4 days until there was a slight improvement. During this time, I had missed my biopsy follow-up appointment to find out the results. The hospital received my results and revealed that I had prostate cancer. This feeling was more surreal than devastating, probably because I was on oxycodone.

They then discharged me (I believe prematurely) with a course of, I think, Amoxicillin. The problem escalated quickly, now with an abscess. Disheartened with my experience at the peripheral hospital, and at the advice of my GP, this time I presented to this city hospital. It was now the end of the year and a very busy time for the staff, but the level of care was fantastic, both by the nursing staff and Urology team. I understandably took a few days to get into surgery given the time of year. The Urology Registrar had great people skills and made me feel that my best interests were being considered. He would assess my situation during surgery, and due to his analysis based on pre-op tests and inspection, I was made aware that an Orchiectomy was possible. I felt gutted. Was I going to lose my masculinity? I would be a liar if I said it didn’t bring a tear to my eye. In this tender moment, the Urology Registrar assured me I would be OK with one testicle. So, the operation went ahead, and my testicle was removed.

All pain rapidly dissipated, and within 2–3 days I had stopped taking opioid painkillers I had been on since the last 3 weeks. Relief at last!!!!! My healing went very well, and I was reasonably positive with my physical changes. I am very thankful to the staff in this hospital, particularly the nursing staff and the Urology team.

Subsequent to that, I had a radical prostatectomy in March. The tumour had been found to be localised, however a small amount of, grade 5 cells, were found in laboratory results. Which apparently means there is an 80% chance of cancer returning within 4–5 years. I do my best to not let it worry me, but sometimes that’s unavoidable. I am continuing my continence therapy and await my fate with a reasonable amount of optimism.’

Learning points.

• Transperineal (TP) biopsy of the prostate has a low reported rate of complications such as sepsis and bleeding.

• However, it is important to recognise that side effects and major adverse events can still occur, such as urinary retention and abscess formation.

• This case highlights the importance of screening for preoperative infection, antibiotics prophylaxis and surgeon familiarity with TP biopsy, as with any other procedure.