|Year : 2012 | Volume
| Issue : 3 | Page : 149-151
Appendiceal mucocele: A rare presentation
Basavaraj M Kajagar, Siddharth Chacko, Utkarsh Gupta, VB Dhaded, A Himanshu
Department of Surgery, Jawaharlal Nehru Medical College, Nehru Nagar, Belgaum, India
|Date of Web Publication||11-Jan-2013|
Basavaraj M Kajagar
Department of Surgery, Jawaharlal Nehru Medical College, Nehru Nagar, Belgaum - 590 010, Karnataka
Source of Support: None, Conflict of Interest: None
Mucocele of the appendix is a descriptive term that implies a dilated appendiceal lumen caused by abnormal accumulation of mucus. Mucocele is found in 0.2-0.3% of all appendectomy specimens. The male to female ratio is 1:4 and the average age at the time of diagnosis is over 50 years.Appendiceal mucocele can be histologically divided into three groups, focal or diffuse, mucosal hyperplasia without epithelial atypia, mucinous cystadenoma with some degree of epithelial atypia and mucinous cystadenocarcinoma.We report a case of benign mucocele of the appendix, which presented as persistent vomiting and lower abdominal pain.
Keywords: Appendectomy, mucinous cystadenoma, mucocele
|How to cite this article:|
Kajagar BM, Chacko S, Gupta U, Dhaded V B, Himanshu A. Appendiceal mucocele: A rare presentation. J Sci Soc 2012;39:149-51
| Background|| |
Mucocele of appendix is rare and difficult to diagnose preoperatively.  Two major pathological mechanisms are thought to be responsible for the formation of appendiceal mucocele. First elevated appendiceal pressures as sequelae of luminal obstruction caused by prior inflammation, mucosal hyperplasia or appendiceal lesions (faecoliths, endometriosis, diverticulae, polyps) and second, tumors of the appendix (carcinoid, cystadenoma, cystadenocarcinoma). Histopathologically these are classified depending on the lining epithelium. These include retention cysts (18%), mucoceles with mucosal hyperplasia (20%), mucinous cystadenomas (32%), and mucinous cystadenocarcinoma (10%). We present a rare case of mucocele of the appendix.
| Case Report|| |
A 60-year-old man presented to us with persistent vomiting with pain in abdomen since 10 days, not being controlled with antiemetics and proton pump inhibitors. The patient had a history of hospitalization in neurosurgicalcenter with history of head injury, but the computed tomography (CT) scanning of the brain was normal. No evidence is suggestive of head injury. Patient was managed conservatively, but nausea and vomiting did not subside. Then the patient came to our hospital, which is a tertiary referral center. The patient had no history of surgery. He noted several months of intermittent nausea and vomiting, which was thought to be due to acid peptic disease.
On examination, he was afebrile and hemodynamically stable. Patient was emaciated and dehydrated (probably due to intermittent nausea and vomiting for several months). There were no signs of internal malignancy. The abdominal examination was normal except for right lower abdominal mild tenderness. Per rectal examination was normal.
Laboratory analysis was unremarkable except for mild hyponatremia and low serum albumin levels, which were corrected accordingly. Plain radiograph of abdomen was normal, and no evidence of intestinal obstruction like multiple air fluid levels and dilated bowel loops. Ultrasonography of the abdomen was normal except for mild ascites probably due to hypoalbuminemia. As we did not get definitive cause for nausea and vomiting, CT abdomen was decided, which revealed 6.0 × 2.5 × 2.7 cm blind ending, tubular, fluid-filled structure that appear to arise from the cecum, consistent with mucocele of the appendix [Figure 1].
Conventional surgery is preferred rather than laparoscopic approach, because laparoscopic approach has increased risk of rupture and subsequent pseudomyxoma formation. Hence we decided to manage by conventional method. The patient underwent elective laparotomy and appendectomy was done as the base was intact. No dilated bowel loops, adhesions or bands [Figure 2], and no signs of inflammation were seen. Exploration of the peritoneum did not show evidence of malignancy. Pathological examination of the surgical specimen revealed benign mucocele of the appendix.
The patient's postoperative course was uneventful, and he was discharged home on postoperative day 10. Postoperative Carcinoembrionic antigen (CEA) levels were normal. Three months after operation, all symptoms had completely resolved and the patient was doing well.
| Discussion|| |
Mucocele of the appendix was first described by Rokitansky (1842) and was formally named by Feren (1876). Since that time, there has been some debate as to the gross diagnosis of mucocele. Some consider the term to encompass a large group of conditions involving the appendix, pancreas, or ovaries, with diverse morphological features and pathogenesis. These conditions share the common feature of obstructive process or hyperplasia of mucinous epithelium or both leading to gross mucinous accumulation. Others consider mucocele to be a strictly neoplastic process that can spread to lymph nodes, extend into surrounding tissue or seed the peritoneum.  The latter description encompasses most mucocele-related diagnoses, and thus, right hemicolectomy is an appropriate first step in managing suspicious mucinous collections of the appendix.
Mucocele of the appendix is a descriptive term for an appendix distended by mucus, secondary to mucinous cystadenoma (63%), mucosal hyperplasia (25%), mucinous cystadenocarcinoma (11%), and retention cyst. 
Mucocele can also occur due to occlusion of the lumen by endometriosis or carcinoid tumor. Overall, appendiceal mucocele makes up about 0.2-0.3% of appendix specimen. The male to female ratio is 1:4 and the average age at the time of diagnosis is over 50 years.  Clinical presentation may include right lower quadrant pain, change in bowel habits, per rectal bleeding or a palpable mass.  Approximately 23-50% of patients are asymptomatic.  In our case, persistent nausea and vomiting were probably due to the mucocele of the appendix which created diagnostic dilemma. Sometimes, patients with mucocele can present with confusing symptoms. Preoperative suspicion and diagnosis of appendiceal mucocele are important. 
The spontaneous and surgery-induced complications of appendiceal mucocele include intestinal obstruction, intussusceptions, intestinal bleeding, fistula formation, and volvulus. The worst complication is pseudomyxoma peritonei, characterized by peritoneal dissemination caused by iatrogenic or spontaneous rupture of the mucocele. The tissues should be handled carefully during surgery to avoid rupture of the mucocele. Hence, conventional surgery is preferred rather than laparoscopic approaches for the treatment in our case. Laparoscopic approach has an increased risk of rupture and subsequent pseudomyxoma peritonei formation. 
Moreno et al.,  suggest conversion to an open appendectomy in case of mucocele when laparoscopic appendectomy is intended. Few authors still recommend a minimally invasive approach in selected patients for this rare entity. However, in these reports laparoscopic approach has been adopted for a small number of patients. Thus, we need a large series to substantiate recommendations of laparoscopic approach.  Conversion to laparotomy should be considered if the lesion is traumatically grasped or if the tumor clearly extends beyond the appendix or if there is evidence of malignancy such as peritoneal deposits.  Appendectomy is advised for focal or diffuse mucosal hyperplasia and cystadenoma when the appendiceal base is intact. Cecal resection is performed for cystadenoma with a large base, and right colectomy is recommended for cystadenocarcinoma. ,,
| Conclusion|| |
Appendiceal mucoceles are rare and are often found incidentally. Incorrect intraoperative handling may lead to major complications. Suggestive and characteristic imaging findings can help establish the preoperative diagnosis of mucocele, highlighting the role radiologists play in preoperative planning and in ensuring good patient outcome. Preoperative recognition of mucocele of the appendix is important because of the possibility of rupture at surgery with development of pseudomyxoma peritonei and to predict malignant transformation.
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[Figure 1], [Figure 2]