abscess, ct scan, diverticulitis, hernia, inguinal mass
J McClenathan. Sigmoid Diverticulitis Simulating Strangulated Inguinal Hernia. The Internet Journal of Surgery. 2012 Volume 28 Number 2.
Most acutely tender masses presenting in the inguinal region are either incarcerated or strangulated hernias, some form of lymph node pathology or rarely inguinal endometriosis with bleeding. In this manuscript, we report a patient with acute swelling and pain in the left inguinal canal that resulted from perforating sigmoid diverticulitis tracking into the inguinal canal. CT scan showed diverticular disease of the sigmoid colon with gas tracking both into the inguinal canal as well as along the psoas muscle. After an abscess was drained in the inguinal canal, laparoscopy and laparotomy confirmed the diagnosis of diverticulitis and led to segmental sigmoid resection, colostomy and Hartmann procedure.
A 43-year-old man was evaluated for left inguinal pain. He had not previously described swelling in the groin. For the week prior to admission, he noted increasing pain and swelling in the left inguinal region. He did not have fever. His abdomen was soft and not tender. The left inguinal region was markedly tender and swollen but there was no redness or drainage. Scrotal exam was normal. He was mildly anemic but WBC was normal. Other lab values were normal. The initial impression was that the patient had an incarcerated or strangulated inguinal hernia.
Abdominal CT scan was obtained (Figures 1, 2). The scan showed that the patient had gas in the inguinal canal tracking from a probable colonic source as well as diverticular disease and gas along the psoas muscle.
The inguinal canal was explored and a large foul-smelling abscess was drained. Laparoscopy and laparotomy were done. The sigmoid colon was dissected from a small defect at the internal ring. The segment of sigmoid diverticulitis was resected and an end sigmoid colostomy and Hartmann procedure were done. The patient recovered.
While complicated diverticular disease is known to cause fistulae to the bladder or the vagina, it is an unusual cause of inguinal complaints. Andrabi recently reported a patient with a pre-existing inguinal hernia where perforating diverticulitis and abscess tracked along the round ligament and incarcerated omentum into the inguinal region.  deVries reported a patient with subcutaneous emphysema in the left groin caused by diverticular abscess tracking through a patent inguinal canal.  Girotto reported three patients treated for acute diverticulitis simulating strangulated inguinal hernia seen at one institution in a one-year period.  Greenberg treated this condition by initial drainage of the infected inguinal area followed by a laparoscopic resection of the diseased colon.  Bunting and colleagues treated their patient with drainage of the hernia, resection of involved sigmoid colon and primary anastomosis.  Our own patient did not know he had a hernia. His groin swelling was initially thought to represent a strangulated hernia. CT scan was helpful in showing that the patient had diverticulitis and he had drainage of the groin abscess, colostomy and Hartmann procedure.
While a tender inguinal swelling is usually the result of an incarcerated or strangulated inguinal hernia, physicians should be aware that complicated diverticular disease can occasionally cause inguinal symptoms. Modern imaging will help to show that the colon is the source of the inguinal symptoms. Once the diagnosis is made, the surgeon should plan treatment of both the primary colon problem and also the infection which presents in the groin.