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OJHAS Vol. 9, Issue 2:
(2010 Apr-Jun) |
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| Mucocele of Appendix
Secondary to Cystadenoma a Diagnostic Challenge |
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Prasad K. Shetty, Ramesh M, Saraswathi Ramesh,
Department
of Pathology, Obstertic and Gynacology and Surgery,
AV Hospital, Bangalore,
India |
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Address For Correspondence |
Surgical Pathologist,
AV Hospital, Patellamma
temple Road
Basvangudi, Bangalore, India
E-mail:
dr.pkshetty@gmail.com |
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Shetty PK, Ramesh M, Ramesh S. Mucocele of Appendix
Secondary to Cystadenoma: a Diagnostic Challenge. Online J Health Allied Scs.
2010;9(2):14 |
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Submitted: Apr 30,
2010; Accepted: Jul 15, 2010; Published: Jul 30, 2010 |
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| Abstract: |
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Mucocele of appendix is uncommon cystic
lesion characterized by distension of the appendiceal lumen with mucus.
Most of them are caused by mucinous cystadenomas and rarely cystadenocarcinomas.
Clinical presentation is varied with more than half being asymptomatic.
We report such a case where initial clinical findings and investigations
suggested an ovarian cyst, and the diagnosis was only made at the time
of surgery. In women presenting with a right iliac fossa mass and clinical
features not indicative of gynaecological pathology, an appendiceal
origin should be considered in the differential diagnosis.
Key Words: Appendix;
Mucocele; Ovarian cyst |
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Mucocele of the appendix
secondary to mucinous cystadenoma is a rare clinical finding. They can
present as a pelvic mass and thus pose a diagnostic challenge.
Currently, the assessment
of right iliac masses relies heavily on ultrasonography as the primary
diagnostic tool. This however may not always identify the origin of
such a mass. In spite of preoperative investigations, the diagnosis
may still remain elusive and may only be made at the time of surgery
A 53 yr old woman came with
history of right-sided abdominal pain, dull and intermittent in nature
since 2 months. Her past history is insignificant. On physical examination,
her abdomen was flat, soft, with normoactive bowel sounds. Tenderness
was noted in the right upper and lower abdomen without rebound pain
or muscle guarding. On pelvic examination, hard, mobile mass approximately
6x4 cms was palpated in the right iliac fossa. Her serum CA 125 was
6.4 IU/ml (Normal <35 IU/ml). An ultrasound scan showed a right sided
mixed echogenic pelvic mass with an echogenic rim, possibly ovarian in origin,
measuring 61 × 43 × 51 mm.(Fig. 1)
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Figure
1: Ultrasound scan showing right sided pelvic cystic mass. |
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Figure 2: Intraoperative photograph of cystic mass arising from
appendix. |
A laparoscopy was planned
with the diagnosis of pelvic mass. A soft cystic mass with a diameter
of approximately 80 x 50 mm with a smooth surface originating from the
appendix in the pelvic region was identified and a routine appendicectomy was
performed.(Fig. 2) Abdominal irrigation was performed and abdominal viscera were evaluated
as normal. Grossly, appendix was globularly enlarged measuring 6x4cms,
outer surface was smooth, on cut opening appendix was cystically dilated
filled with large amount of mucin, wall was 6mm thick.(Fig 3)
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Figure 3: Gross
photograph of cystically dilated appendix filled with abundant mucin |
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Figure 4,5:
10x and 40x microphotograph showing cystadenoma appendix lined by atypical
mucinous lining epithelium |
On Microscopy appendix showed atypical lining mucinous epithelium predominently
in a papillary configuration, lining cells were stratified columnar
cells with basal, elongated, hyperchromatic nuclei, with abundant apical
mucin, muscularis propria is thinned out with hyalinization.(Fig. 4,5)
Mucocele of the Appendix
make up about 0.2%–0.3% of appendicectomies. Appendiceal mucoceles
show a female predominance of 4:1. The average age at the time of diagnosis
is 54 years for benign mucoceles and 64 years for malignant disease.[1]
The most common presentation of symptomatic appendiceal mucocele patients
is acute or chronic right lower quadrant abdominal pain, as occurred
with our patient.[2,3] An intra-abdominal mass is palpated
by the examining physician in half of cases.[4] Nausea and
vomiting, as well as altered bowel habits are often reported.[5,6]
An association between appendiceal mucocele and synchronous colon neoplasms
has been previously noted. The most common synchronous neoplasms occur
in the large bowel (19.5%-21%).[7] A correct pre-operative
diagnosis of appendiceal mucocele is difficult due to the nonspecific
symptoms.[8] Computed tomography (CT), ultrasonography (US),
and colonoscopy have all been used to describe these tumors. Unfortunately
none of these is entirely conclusive. [1, 8]
In our case ultrasonography could not provide a preoperative diagnosis.
Surgical excision of
mucocele of appendix can be either by laparotomy or Laparoscopy.
Laparoscopic surgery provides the advantages of good exposure and evaluation
of entire abdominal cavity, as well as more rapid recovery with avoidance
of a large incision and a better cosmetic outcome. However careful handling
of the specimen is recommended as spillage of the contents can lead
to pseudomyxoma peritonei.[9,10]
Histopathologic classification
of appendiceal mucoceles is dependent on the characteristics of their
lining epithelium; these include retention cysts (18%), mucoceles with
mucosal hyperplasia (20%), mucinous cystadenomas (32%), and mucinous
cystadenocarcinomas (10%). Classification is important; because the
course of the disease and prognosis are related to these subtypes.10
Simple mucoceles (retention cysts) are characterized by degenerative
epithelial changes and may result from appendiceal obstruction and distension.
There is no evidence of hyperplasia or neoplasia of the mucosa. Hyperplastic
mucoceles are sessile or pedunculated lesions that represent hyperplastic
polyps of the colon and are not known to have any malignant potential.
Mucinous cystadenomas also have been referred to as low-grade appendiceal
mucinous neoplasms. They typically are circumferential cystic lesions
composed of mucin rich epithelium. While mucinous cystadenomas can be
considered the equivalent of adenomatous colon polyps. The 5-year survival
rate for simple or benign neoplastic mucocele ranges from 91% to 100%.[5-7]
In conclusion mucocele
of appendix is very rare. It is very difficult to diagnose preoperatively
in women as it mimics adnexal mass. The mucocele of the appendix must
be considered in patients with advanced age; especially in female, with
atypical ultrasonographic appearance; or a right adnexal mass.
- Kalu E, Croucher C. Appendiceal
mucocele: A rare differential diagnosis of a cystic
right adnexal mass. Arch Gynecol Obstet 2005; 2771:86-8
- Isaccs KL, Warshauer DM. Mucocele
of the appendix: computed
tomographic, endoscopic, and pathologic correlation. Am
J Gastroenterol 1992;87:787-9.
- O’Sullivan MJ, Kumar U,
Kiely EA. Ureteric obstruction with
mucocele of the appendix due to endometriosis. BJOG
2001;108:124-5.
- Coulier B, Pestieau S, Hamels
J, Lefebvre Y. US and CT diagnosis
of complete cecocolic intussusception caused by an
appendiceal mucocele. Eur Radiol 2002;12:324-8.
- Chiu CC, Wei PL, Huang MT,
Wang W, Chen TC, Lee WJ.
Laparoscopic resection of appendiceal mucinous cystadenoma. J Laparoendosc
Adv Surg Tech A. 2005;15:325-8.
- Carr NJ, McCarthy WF, Sobin
LH. Epithelial noncarcinoid tumors
and tumor-like lesions of the appendix. A clinicopathologic
study of 184 patients with a multivariate analysis
of prognostic factors. Cancer 1995;75:757-68.
- Wolff M, Ahmed N. Epithelial
neoplasms of the vermiform appendix
(exclusive of carcinoid). II. Cystadenomas, papillary
adenomas, and adenomatous polyps of the appendix. Cancer
1976;37:2511-22.
- Shukunami K, Kaneshima M,
Kotsuji F. Preoperative diagnosis and
radiographic findings of a freely movable mucocele of
the vermiform appendix. CARJ 2000;51:281-2.
- Dachman AH, Lichtenstein JE,
Friedman AC. Mucocele of the appendix and pseudomyxoma peritonei. Am J Roentgenol. 1985;144:923–29.
- Navarra G, Asopa V, Basaglia
E, Jones M, Jiao LR, Habib NA. Mucous cystadenoma of the appendix: is
it safe to remove it by a laparoscopic approach? Surg Endosc. 2003;17:833–4.
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