Acute urinary retention secondary to perforated diverticulitis misdiagnosed as acute prostatitis

Abdominal abscess resulting from a perforated diverticulitis has never been reported as a cause of acute urinary retention. Our patient is the first case to be reported. Because of the atypical presentation, he was initially misdiagnosed and treated as having acute prostatitis. Emergency physicians should have a high index of suspicion. Detailed history, abdominal sonography, and digital examination are helpful in diagnosing this disease. Acute diverticulitis is becoming more common in young adults [1]. Clinical symptoms depend on the degree and extent of inflammation. Abdominal pain is the most common symptom, followed by nausea, vomiting, and diarrhea. If free perforation occurs, diffuse peritonitis or a palpable mass may be noted [2]. Acute urinary retention as the presentation in a patient with complicated diverticulitis has never been reported in the past. We present a young adult who developed fever, dysuria, and acute urinary retention because of an undiagnosed perforated diverticulitis with a subsequent huge abscess formation. He was initially misdiagnosed as having acute prostatitis. A 36-year-old man, without remarkable medical history before coming to our emergency department (ED), presented with the complaints of progressive lower abdominal pain and difficulty in urination for 2 weeks. The symptoms initially occurred after defecation and became worse gradually. Low-grade fever was also noted. He visited our ED for help on the fifth day, and acute urinary retention was impressed. Six hundred milliliters of residual urine was catheterized. He was referred to the outpatient department of urology for further treatment. Blood analysis revealed leukocytosis (white blood cell count of 14 190/μL), and urine analysis showed a white blood cell count of 3 to 5 per high-power field. Acute prostatitis was impressed by a urologist, and oral antibiotic was prescribed. Fever subsided after medication, but his symptoms got worse. He denied nausea, vomiting, or diarrhea during this period. In our ED, his vital signs included a temperature of 36.3°C (97.3°F), pulse rate of 108 beats per minute, respiratory rate of 16/min, and blood pressure of 106/53 mm Hg. Physical examination was unremarkable except for mild suprapubic tenderness, without rebound or muscle rigidity. Digital examination revealed a normal prostate, but a painless mass was noted above it. Laboratory tests showed a white blood cell count of 9100/μL (segment form, 51%; band form, 6%), a platelet count of 482 000/μL, and a C-reactive protein level of 6.52 mg/dL. His biochemical profiles and coagulation function were within reference ranges. An echogenic mass with air in the retrovesicular pouch was noted by sonography. A computed tomographic scan revealed a 17.5-cm abscess in the intraperitoneal portion of the pelvic cavity that extends to the rectovesical pouch, and the urinary bladder was severely compressed (Fig. 1). Drainage of the abscess and sigmoid colostomy were performed, and a perforated sigmoid colon diverticulitis with abdominal abscess was impressed. His urinary symptoms totally subsided after the operation. Bacterial culture of the aspirated pus revealed Group D streptococci. The follow-up lower gastrointestinal series showed sigmoid diverticulosis. The patient was discharged uneventfully after the operation. Abdominal abscess is an extremely rare etiology of acute urinary retention. All reported cases were caused by a ruptured appendicitis [3-9], and few patients were older than 18 years [7-9]. Our case represents the first patient with acute urinary retention caused by complicated diverticulitis. Acute diverticulitis is prevalent in the elderly, and the incidence is only 12% in those younger than 40 years. The disease is more aggressive in young patients, and surgical intervention is frequently needed. Abdominal abscess and peritonitis are the most common indications for operation in young patients [1]. Most patients with diverticulitis present with abdominal pain, gastrointestinal symptoms, and fever. Palpable abdominal mass might be noted if abscess occurred. The etiology of urinary retention is believed to be urinary tract obstruction caused by compression on the bladder and urethra or spasticity of the pelvic floor and external urethral sphincter [9]. Acute prostatitis is the most common urological diagnosis in men younger than 50 years [10]. Our patient is a young man who presented with urinary symptoms, low abdominal pain, and fever. Acute prostatitis is highly suspected because of the age and symptoms. However, gastrointestinal disease should be considered because his symptoms occurred after defecation, and his urinalysis result is normal. Persistent abdominal pain is also a hint. Digital examination, prostate-specific antigen, and sonography are not checked at first to confirm the disease. Abdominal abscess resulting from a perforated diverticulitis is a rare cause of acute urinary retention. Emergency physicians can minimize delay or misdiagnosis by: (1) always maintaining a high index of suspicion in all cases of urinary retention and abdominal pain; (2) performing a careful and thorough history and physical examination, especially digital examination; and (3) performing abdominal sonography in each patient with urinary retention to find out other obstructive lesions. Timely surgical consultation is needed in these patients.