Mucinous cystadenoma of the appendix can be asymptomatic or may present with abdominal pain, an abdominal mass, per rectal bleeding, ureteral obstruction, hematuria or intussusception [1
]. Our patient had a 15-day history of pain in her RIF. She had also been experiencing some heaviness in the lower abdomen for six months. Although the presence of symptoms in a patient with an appendiceal mucocele has been reported to be associated with a higher incidence of cystadenocarcinomas [9
], this does not appear to be a useful guide in the pre-operative assessment of patients with appendiceal mucoceles.
Colonoscopy and CT scan were used as the initial investigative modalities in our patient. CT scan findings in patients with mucinous cystadenomas include cystic masses with low attenuation, irregular wall thickening and absence of associated appendiceal inflammation [1
]. Mural calcification has been reported with a high frequency (50%) in patients with appendicular mucinous cystadenomas [10
]. It is also important to note that the varying thickness of the wall of the mass on CT scans has not been shown to correlate with malignancy. However, contrast enhancing nodules on CT scans may be suggestive of cystadenocarcinomas [1
]. A colonoscopy performed on our patient revealed external compression of the cecum with normal overlying mucosa. We then proceeded with a CT scan which showed an appendicular mucocele with extensive mural calcification and some periappendiceal stranding.
Both mucinous cystadenomas and cystadenocarcinomas have the potential to cause peritoneal seeding leading to pseudomyxoma peritonei. However, survival in patients with a cystadenoma is better compared to patients with its malignant counterpart when considering pseudomyxoma peritonei [1
It is important to distinguish between mucinous cystadenomas and mucinous cystadenocarcinomas. However, this distinction remains elusive and cannot be established with any degree of reliability if we are to depend solely on physical examination findings and radiological imagings. Histopathological examination is instrumental in achieving an accurate diagnosis. Herein, lies the dilemma for the surgeon because of the nebulous nature of the distinction between these entities in the pre-operative setting.
The best surgical management of a patient with an appendiceal mucocele remains a subject of controversy. There is little consensus on the optimal choice of procedure (right hemicolectomy versus appendectomy) as well as the approach (laparoscopic versus laparotomy). While earlier data have shown a survival advantage associated with right hemicolectomy, more recent prospective data findings do not report any survival advantages in a patient with pseudomyxoma peritonei syndrome and appendiceal mucinous carcinomatosis undergoing a right hemicolectomy [13
In general, certain principles must be kept in mind while operating on patients with appendiceal mucoceles. It is important to exercise care in handling tissues intra-operatively to reduce the risk of dissemination of mucin-producing epithelium [1
]. Zagrodnik et al
. have supported the choice for appendectomy with mesoappendix excision in the absence of local invasion or cecal involvement for appendiceal masses [1
]. Gupta et al
. have advocated the removal of mucoceles of less than 2 cm in diameter using this approach [7
]. However, mucoceles of less than 2 cm in diameter are usually simple retention cysts and this choice of surgical approach based on size alone does not appear to be helpful considering that hyperplastic epithelium, cystadenoma and cystadenocarcinoma are more likely to be greater than 2 cm in size [3
The presence of local invasion and cecal involvement are two indications in the literature that necessitate employment of right hemicolectomy for appendiceal mucoceles [1
]. An open approach has been favored by some authors as being a definitive and safe maneuver which allows better visualization of the abdominal cavity. This advocacy is supported by the incidence of peritoneal implants and inadvertently missed lesions after laparoscopy [1
]. The right retrohepatic space, pelvis, omentum and left paracolic space all merit meticulous inspection for mucinous fluid collection. The appendiceal lymph nodes and appendiceal stump should also be carefully inspected [9