A rare case of a multi-focal corpora cavernosal abscess.

Introduction

Review of the current literature suggests that an abscess originating in the corpus cavernosum is rare, with a paucity of reported cases in the literature. Upon reviewing the evidence, there have been reported cases of cavernosal abscess following a local nidus for infection including trauma or local injection, however few have reported a spontaneous abscess formation within the penile corporal cavernosal region. Here, we present the case of a 49-year old previously fit and healthy gentleman, with a spontaneous bilateral penile cavernosal abscess. Magnetic resonance (MR) imaging confirmed the diagnosis of an extensive abscess within the corpora cavernosa bilaterally. Subsequent incision and drainage of the abscess was performed followed by a 5 week course of antibiotics. Microscopy & culture demonstrated Streptococcus Anginosus in both blood cultures and wound pus swabs. Of note, lengthy critical care input was also required for inotropic support secondary to significant sepsis.

Case report

A 49-year-old gentleman, known to be previously fit and well, presented to the emergency department with a one-week history of a progressively worsening swollen and painful scrotum and penis. Of note, no irritative urinary symptoms were noted. He was diagnosed with an infective episode of balanitis one month prior in the emergency department and was subsequently discharged with a course of Ciprofloxacin. There was no significant medical or surgical history with an American Society of Anesthesiologists (ASA) score of 1.

On examination, he was pyrexial with temperature of 39 °C and had a swollen tender scrotum and penis with significant scrotal oedema. Of note, there were no gangrenous patches or skin breaks on the penile or scrotal skin, to suggest necrotizing fasciitis or Fournier's gangrene. Laboratory results showed raised white well count of 25.1 × 109/L and C-reactive protein of 269mg/L. Urine dipstick was unremarkable. Blood cultures were taken and empirical antibiotics were commenced (intravenous Gentamicin and Co-amoxiclav).

A scrotal ultrasound scan revealed scrotal cellulitis, oedema and lymphadenopathy in the right inguinal canal. Subsequent CT thorax, abdomen and pelvis was performed which did not reveal any intra-abdominal pathology. An echocardiogram and bilateral lower limb doppler study were also performed and excluded infective endocarditis and deep vein thrombosis respectively.

Blood cultures revealed Streptococcus Anginosus therefore the antibiotics were rationalised to Benzylpenicillin and Clindamycin on microbiological advice. A repeat ultrasound scan 3 days later demonstrated skin cellulitis and suggested an abscess in the root of the penis and inguinal canal with a reactive hydroceles bilaterally (Fig. 1). There was concern regarding urethral and ischiorectal involvement of the abscess cavity so an MRI was later performed the same day which displayed a 10 × 6cm abscess abutting the ventral aspect of the root of the penis extending to perineum and base of scrotum, displacing but not invading the urethra (Fig. 2). The MR scan was important to ensure the appropriate surgical teams were involved at an early stage.

Fig. 1

Ultrasound imaging of the testes and penile root. Illustrating evidence of bilateral hydroceles and fluid collection in penile base/scrotum, suggestive of an abscess. a: Collection of thickened fluid in penile root/base of scrotum. b: Left reactive hydrocele. c: thickened and oedematous subcutaneous tissue in scrotum. d: Right sided reactive hydrocele.

Fig. 2

Magnetic resonance imaging demonstrating evidence of abscess within corpora cavernosa extending from the penile root. a: Coronal images revealing oedema and induration of penile shaft. b: Extensive collection and air locules extending from penile root into scrotum. c: Abscess cavity at penile root. d: Abscess cavity tracking into corpora cavernosum.

Following the MRI scan, incision and drainage of the abscess was undertaken in theatre. Two days later he returned to theatre again for wound exploration and washout as a second look procedure. Further, third surgical exploration four days after the initial surgery showed a necrotic corpus cavernosum and possible ischiorectal involvement. A flexible sigmoidoscopy showed a normal recto-sigmoid colon up to 15cm. A suprapubic catheter was sited to allow for comprehensive debridement of the necrotic areas within the corpora. Due to the extensive necrosis within the corpora as well as perineum, a further eight operative attempts at debridement and wound washouts were required before the patient showed signs of clinical improvement. Antibiotic therapy continued for 5 weeks with the patient being discharged after 6 weeks. Unfortunately, the patient declined to attend follow up, so we have little information regarding reconstructive options.

Discussion

There is a paucity of reported cases documenting abscesses of the corpus cavernosum. Upon reviewing the literature, the most common presentation of a corpus cavernosum abscess is penile pain and swelling. Many cases are spontaneous. Some reported cases are associated with priapism, intra-cavernous injection therapy with papaverine or alprostadil,, trauma, or foreign bodies such as penile prosthesis 1, 2, 3. There are case reports of secondary corpus cavernosum abscess developed from an intra-abdominal abscess. Staphylococcus aureus is the most common causative organism amongst reported cases, followed by Streptococci, Fusibacteria and Bacteroides.

The Streptococcus milleri group (SMG) comprising of S. anginosus, S. constellatus and S. intermedius are commonly found as part of the normal oropharynx and gastrointestinal tract flora. However, they are commonly associated with abscess formation. The mainstay of management in SMG infection is for incision and drainage of the primary abscess whilst commencing on appropriate antibiotic therapy.,

To our knowledge, our case is one of the only few reported cases of cavernosal abscess secondary to Steptococcus anginosus infection in a previously fit and healthy individual. In our patient, clinical diagnosis was challenging even with the aid of ultrasonography, eventually leading to the use of MRI for a definitive diagnosis of the abscess. He was promptly brought to theatre for abscess drainage and started on empirical antibiotics. However, due to the severity of the condition, he required further wound washouts. We understand the potential of post-operative complications involved with drainage of a penile abscess, such as penile deviation due to secondary fibrosis, erectile dysfunction or recurrence of abscess. However, due to our patient's loss of follow up, we are unable to establish any long-term complications or reconstructive options in our case.

Conclusion

Abscess of corpus cavernosum is an uncommon presentation but with potential serious and significant complications. It should be considered as a differential diagnosis in patients presenting with an acute onset of a swollen painful penis. Prompt diagnosis and treatment with antibiotics and consideration of early incision and drainage, or aspiration is required.