The conservative management of periappendiceal abscesses is gaining favour due to decreased morbidity and improved clinical outcomes for patients. Occasionally however an abscess can mask underlying sinister pathology. In this article, we highlight two cases of appendiceal adenocarcinoma that were initially diagnosed as periappendiceal abscesses and managed conservatively with percutaneous drainage. We also discuss clinical and imaging features that may assist with identifying a hidden malignancy when presented in these situations.
Patients presenting with periappendiceal abscesses are generally treated conservatively [
Approximately 20 patients underwent image guided drainage in our institution for periappendiceal collections between 2013 and 2015 (2 years). We present two cases where the initial diagnosis was periappendiceal abscess due to acute appendicitis and a drain was inserted. There was persistent abscess collection despite drainage in these cases and subsequent histology revealed an underlying malignancy.
A 76-year-old man presented with a one-week history of intermittent fever, nausea, and right iliac fossa (RIF) pain. Initial CT scan performed at an external centre showed a large irregular collection in the RIF, compatible with an abscess, likely from a perforated appendix. He was referred to our institution and underwent CT-guided drainage of the collection (Figure
Coronal reconstruction demonstrating a drainage tube within the appendiceal collection.
An outpatient CT scan performed one month after the drainage for recurrent symptoms revealed a persistent abscess in the retrocaecal region, now extending to involve the pelvic side wall and iliopsoas muscles (Figure
Coronal reconstruction demonstrating a persistent abscess in the retrocaecal region, with new extension to involve the pelvic side wall and iliopsoas muscles.
Another follow-up in the general surgery clinic showed persistent symptoms and continuous drain output, and he underwent an extended right hemicolectomy approximately 3 months from the date of initial presentation. Intraoperative findings revealed a large, polypoid caecal tumour with a 2 cm defect and contained abscess posteriorly extending into the lateral abdominal wall, close to the iliac crest. Histology confirmed this to be a mucinous adenocarcinoma.
A 49-year-old lady presented to our emergency department with a one-week history of fever and localised RIF pain. CT scan performed on admission delineated a dilated and ill-defined appendix with focal perforation at its tip (Figure
Thickened and inflamed appendix with a focal perforation of the tip with an adjacent abscess.
She represented approximately 2 weeks later due to worsening symptoms. Repeat CT scan (Figure
Repeat CT scan demonstrates a largely stable periappendiceal collection.
She returned another two and a half months later for nonresolving symptoms. The repeat CT scan (Figure
A new hypodense lesion in caudate lobe of the liver suspicious for metastasis.
A persistent periappendiceal collection is again seen. New findings include small bowel obstruction as well as nodules adjacent to the collection and along the track of previous drain insertion.
The patient underwent an open right hemicolectomy with en bloc right salpingooophorectomy. Intraoperative findings revealed a mass involving and encasing the terminal ileum as well as involving the right fallopian tube, ovary, and ureter and extending into the pelvic side wall. A separate appendix was not identified within the mass. Multiple peritoneal nodules were evident in the omentum and as far up as the hepatic dome. The histology specimen was confirmed to be an adenocarcinoma.
Acute appendicitis is the result of luminal obstruction. This is typically caused by faecolith or lymphoid hyperplasia and less frequently by foreign body impaction or parasites [
CT scans are routinely performed nowadays both to diagnose acute appendicitis and to identify mimics such as right ureteric calculus, epiploic appendagitis, torsion of a Meckel’s diverticulum, mesenteric adenitis, inflammatory bowel disease, colitis, gynaecological disorders, and right-sided diverticulitis [
Current literature supports nonsurgical management of appendiceal abscesses [
A case report by Fusari et al. described findings of acute appendicitis on a preoperative CT scan with a loculated fluid collection and lymphadenopathy adjacent to the appendix that was found to be a signet cell carcinoma on histology [
Multiple case studies are available describing imaging findings of pathology at or near the appendix such as mucocoeles, mucinous epithelial neoplasms, soft-tissue masses with nonmucinous or colonic-type epithelial neoplasms, carcinoid tumours, and lymphoma causing diffuse mural thickening and dilation of the appendiceal lumen [
Imaging alone however is inadequate for the follow-up of complicated appendicitis. There is evidence to support an early colonoscopy and an interval appendectomy in appropriate patients. A study by Lai et al. [
Approval from our institutional review board is not required for a retrospective case report.
The authors declare that they have no financial interest.