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A 27-year-old male patient presents to the emergency department with severe abdominal pain that has persisted for 3 days. He says he is otherwise in good health. He has had no change in bowel habits and is afebrile.

The patient reports having seen his physician on the previous day, due to crampy pain in the periumbilical area. At that time, he was diagnosed with gastroenteritis and sent home with antibiotics (ciprofloxacin and metronidazole).

When the patient presents to the emergency department, his pain has shifted to the lower left quadrant of his abdomen. Findings on physical palpation of the abdomen are unremarkable, beyond guarding in the lower left abdomen. The patient has no localized tenderness over McBurney's point. Laboratory tests included a complete blood count, which showed a normal white blood cell (WBC) count of 8,500 mL of blood with a left shift. His C-reactive protein level is elevated, at 196 mg/L.

Diagnosis

Computed tomography (CT) scan with intravenous contrast of the abdominal-pelvic area reveals midgut malrotation of the small bowel to the right and a left-sided cecum. Physicians note an inflamed left-sided appendix complicated by a periappendiceal phlegmon formation.

Treatment and Outcome

The patient is admitted for emergency surgery, and his appendix is removed laparoscopically. Trocars are inserted in the following areas: 1 x 10 mm in the infraumbilical area, another 10 mm in the right lower quadrant area, and a final 5 mm in the suprapubic area.

Surgeons confirm the presence of the ileocecal valve and cecum on the left side adjacent to the sigmoid. They note an inflamed appendix and observe a hard structure encompassing its tip, reminiscent of a phlegmon. The surgeons devascularize the mesoappendix and transect the appendix using two endoloops, and remove the specimen using an endobag. After confirming adequate hemostasis, all the layers of the abdominal wall are closed.

Case Follow-up

The following day, the patient is started on a clear fluid diet with gradual progression to include small amounts of easily digested foods. Assessment of the patient on the following day shows that he is in very good physical condition and is tolerating his diet. He is discharged home.

Based on the patient's pathology results, surgeons conclude that the patient had acute diverticular appendicitis with peri-appendiceal mucocele with no evidence of lymphovascular invasion or signs of malignancy.

Discussion

Acute pain or tenderness in the left lower quadrant of the abdomen has a variety of possible etiologies, including left-sided primary epiploic appendagitis, acute diverticulitis (most commonly seen in older patients), a long right-sided acute appendicitis that projects into the lower left quadrant, and a left-sided acute appendicitis.¹

Acute appendicitis is a common reason for emergency surgery – and when diagnosed quickly, the prognosis is favorable. Delays in diagnosing acute appendicitis can have serious consequences – 36 hours after onset of symptoms, the risk of perforation increases by 5% every 12 hours.²

A thorough clinical examination combined with imaging is the usual approach to diagnosing appendicitis. Of imaging modalities, the gold standard is abdominal-pelvic with intravenous contrast, which can reduce the time to diagnosis and is highly accurate in diagnosing acute appendicitis.^3,4 Data suggests a potential accuracy of 98% when abdominal CT scan is combined with a physical examination.⁵

Despite well-established diagnostic criteria, approximately one in four patients who present with acute appendicitis are .⁶ While expert opinions vary regarding the utility of the , it continues to have diagnostic value on its own or in addition to imaging.⁷

Addressing Delayed Diagnosis

Left-sided acute appendicitis is an atypical presentation that increasingly is implicated in delayed diagnosis. Two very rare congenital abnormalities identified in left-sided acute appendicitis include midgut malrotation and situs inversus.⁸ Left-sided acute appendicitis should be considered in any patient presenting with acute lower left quadrant pain -- and particularly in younger patients.

The authors reporting this case observed that delayed diagnosis and surgery are more likely in patients who present atypically, are not thoroughly examined, are given narcotic pain medication and then discharged from the emergency department, are diagnosed as having gastroenteritis, and do not receive appropriate discharge or follow-up instructions.⁶

Surgical Management Options

The authors reporting this subsequently reviewed the literature and identified simple appendectomy as the optimal approach for cases that involve the following:

• Benign appendiceal mucocele

• Negative margins of resection

• No signs of perforation, and more than 2 cm away from the base⁹

In contrast, cases that involve a perforated appendix, and/or have positive resection margins, and/or appendiceal lymphadenopathy suggest that the preferred options would be a right colectomy associated with a debulking cytoreductive surgery, in addition to heated intra-peritoneal chemotherapy or early postoperative intra-peritoneal chemotherapy.¹⁰

In the case of perforation with a positive cytology but negative resection margins and negative appendiceal lymph nodes, only appendectomy and a debulking cytoreductive surgery and heated intra-peritoneal chemotherapy or early postoperative intra-peritoneal chemotherapy would be required.¹⁰

While laparoscopy is increasingly used for initial surgical management of appendiceal mucocele, the authors reporting this case recommend using the open approach for any of the following:

• Trauma to the surgical specimen while being grasped

• Clear extension of the tumor beyond the appendix

• Signs of disseminated malignant disease including peritoneal deposits¹¹

Conclusion

The authors concluded that left-sided acute appendicitis is increasingly implicated in misdiagnosis, and should be considered in patients with left lower quadrant pain.

References

1. Hou SK, et al. Diagnosis of appendicitis with left lower quadrant pain. J Chin Med Assoc 2005; 68(12): 599–603

2. Wagner PL, et al. Defining the current negative appendectomy rate: For whom is preoperative computed tomography making an impact? Surgery 2008; 144(2): 276–282

3. Rao PM, et al. Sensitivity and specificity of the individual CT signs of appendicitis: Experience with 200 helical appendiceal CT examinations. J Comput Assist Tomogr 1997; 21(5): 686–692

4. Stroman DL, et al. The role of computed tomography in the diagnosis of acute appendicitis. Am J Surg 1999; 178: 485–489

5. Jones K, et al. Are negative appendectomies still acceptable? Am J Surg 2004; 188(6): 748–754

6. Kryzauskas M, et al. Is acute appendicitis still misdiagnosed? Open Med (Wars) 2016; 11(1): 231–236

7. Ozsov Z, Yenidogain E. Evaluation of the Alvarado scoring system in the management of acute appendicitis. Turk J Surg 2017; 33(3): 200-204

8. Akbulut S, et al. Left-sided appendicitis: Review of 95 published cases and a case report. World J Gastroenterol 2010; 16(44): 5598–5602

9. Saliba C, et al. Pitfalls of Diagnosing Left Lower Quadrant Pain Causes: Making the Uncommon Common Again. Am J Case Rep 2019; 20: 78-82

10. Palanivelu C, et al. Laparoscopic right hemicolectomy for mucocele due to a low-grade appendiceal mucinous neoplasm. JSLS 2008; 12(2): 194–197

11. Navarra G, et al. Mucous cystadenoma of the appendix: Is it safe to remove it by a laparoscopic approach? Surg Endosc 2003; 17(5): 833–834

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