1. science
2. medicine
3. surgery

Case Report
Appendiceal mucocele: benign and malignant
Yasir S Abdelhadi, FRCSI, Abubaker AM Elhaj, MRCSI MD
Department of Surgery, Royal Care International Hospital Khartoum - Sudan
‫ اﻟﺤﻤﻴﺪة واﻟﺨﺒﻴﺜﺔ‬: ‫اﻟﻘﻴﻠﺔ اﻟﻤﺨﺎﻃﻴﺔ اﻟﺰاﺋﺪﻳﻪ‬
(‫ زﻣﻴﻞ اﻟﻜﻠﻴﻪ اﻟﻤﻠﻜﻴﻪ ﻟﻠﺠﺮاﺣﻴﻦ)اﻳﺮﻟﻨﺪا‬,‫ﻳﺎﺳﺮ ﺳﻴﺪأﺣﻤﺪ ﻋﺒﺪاﻟﻬﺎدي‬
(‫ اﻟﺪآﺘﻮراﻩ اﻟﻺآﻠﻴﻨﻴﻜﻴﻪ ﻓﻲ اﻟﺠﺮاﺣﻪ اﻟﻌﺎﻣﻪ)اﻟﺴﻮدان‬,(‫ﻋﻀﻮ اﻟﻜﻠﻴﻪ اﻟﻤﻠﻜﻴﻪ ﻟﻠﺠﺮاﺣﻴﻦ)اﻳﺮﻟﻨﺪا‬,‫أﺑﻮﺑﻜﺮ ﻋﺒﺪاﻟﺮﺣﻤﻦ ﻣﺤﻤﺪ اﻟﺤﺎج‬
.‫اﻟﺴﻮدان‬-‫ اﻟﺨﺮﻃﻮم‬,‫ ﻣﺴﺘﺸﻔﻰ روﻳﺎل آﻴﺮ اﻟﻌﺎﻟﻤﻴﻪ‬,‫ﻗﺴﻢ اﻟﺠﺮاﺣﻪ‬
‫اﻟﻤﻠﺨﺺ‬
‫ اﻟﻮرم اﻟﻐﺪي آﻴﺴﻲ ﻣﺨﺎﻃﻲ‬.‫ هﻮ ﻣﺮض ﻧﺎدر اﻟﺤﺪوث وهﻮ ﻣﺼﻄﻠﺢ وﺻﻔﻲ ﻟﺘﻮﺳﻊ ﺗﺠﻮﻳﻒ اﻟﺰاﺋﺪﻩ اﻟﺪودﻳﻪ ﻧﺘﻴﺠﺔ ﻻﻧﺴﺪادﻩ ﺑﺎﻓﺮازات ﻣﺨﺎﻃﻴﻪ‬: ‫ﻣﻘﺪﻣﻪ‬
.‫ ﺗﻜﺘﺸﻒ ﻋﺮﺿﻴﺎ أﺛﻨﺎء اﻟﺠﺮاﺣﻪ‬%50 ‫ اﻷﻋﺮاض اﻟﺴﺮﻳﺮﻳﻪ ﻋﺎدة ﻏﻴﺮ ﻣﺤﺪدﻩ ﻓﺄآﺜﺮ ﻣﻦ‬.‫ ﻣﻦ اﻟﺤﺎﻻت‬%70 ‫ اﻟﻰ‬%60 ‫واﻟﺴﺮﻃﺎﻧﻪ اﻟﻐﺪﻳﻪ ﻣﺨﺎﻃﻴﻪ ﻳﻤﺜﻼن ﻣﻦ‬
‫ اﻟﺤﺎﻟﻪ اﻷوﻟﻰ آﺎﻧﺖ ﺗﺸﻜﻮ ﻣﻦ أﻟﻢ ﻓﻲ اﻟﺠﻬﺔ اﻟﻴﻤﻨﻰ أﺳﻔﻞ اﻟﺒﻄﻦ وﺗﻢ اﻟﺘﺸﺨﻴﺺ ﺑﻨﺎء ﻋﻠﻰ اﻷﺷﻌﻪ اﻟﻤﻘﻄﻌﻴﻪ ﻟﻠﺒﻄﻦ‬,‫ ﻧﻘﺪم اﺛﻨﻴﻦ ﻣﻦ اﻟﺤﺎﻻت اﻟﻨﺎدرﻩ‬: ‫ﻋﺮض ﺣﺎﻟﻪ‬
.‫وأﺟﺮﻳﺖ ﻟﻬﺎ ﻋﻤﻠﻴﺔ إﺳﺘﺌﺼﺎل ﻟﻠﺠﺰء اﻷﻳﻤﻦ ﻣﻦ اﻟﻘﻮﻟﻮن وآﺎﻧﺖ ﻧﺘﻴﺠﺔ اﻷﻧﺴﺠﻪ ورم ﻏﺪي آﻴﺴﻲ ﻣﺨﺎﻃﻲ‬
‫أﻣﺎ اﻟﺤﺎﻟﻪ اﻟﺜﺎﻧﻴﻪ ﻓﻘﺪ ﺗﻢ ﺗﺸﺨﻴﺼﻬﺎ ﻋﺮﺿﻴﺎ ﺑﻌﺪ اﻷﻃﻼع ﻋﻠﻰ اﻷﺷﻌﻪ اﻟﻤﻘﻄﻌﻴﻪ ﻟﻠﺒﻄﻦ وﺑﺎﻟﻜﺸﻒ اﻟﺴﺮﻳﺮي ﺗﺒﻴﻦ وﺟﻮد ورم أﺳﻔﻞ اﻟﺒﻄﻦ وأﺟﺮﻳﺖ ﻟﻬﺎ ﻋﻤﻠﻴﺔ‬
.‫إﺳﺘﺌﺼﺎل ﻟﻠﺠﺰء اﻷﻳﻤﻦ ﻣﻦ اﻟﻘﻮﻟﻮن وﺟﺰء ﻣﻦ اﻟﻘﻮﻟﻮن اﻷﻳﺴﺮ وآﺎﻧﺖ ﻧﺘﻴﺠﺔ اﻷﻧﺴﺠﻪ ﺳﺮﻃﺎﻧﻪ ﻏﺪﻳﻪ ﻣﺨﺎﻃﻴﻪ‬
.‫ ﻧﻮﺻﻲ ﺑﺈزاﻟﺔ اﻟﺠﺰء اﻷﻳﻤﻦ ﻣﻦ اﻟﻘﻮﻟﻮن ﻓﻲ آﻞ اﻟﺤﺎﻻت اﻟﺘﻲ ﻳﺸﺘﺒﻪ ﻓﻲ أﻧﻬﺎ أورام ﻏﺪﻳﻪ ﻣﺨﺎﻃﻴﻪ‬: ‫اﻻﺳﺘﻨﺘﺎج‬
Summary
Keywords: Appendix, mucocele, mucinous
cystadenoma,
cystadenocarcinoma,
hemicolectomy.
Appendicular mucocele is a rare lesion. It is a
descriptive term denoting an obstructive
dilatation of the appendicular lumen by
mucinous secretions. Mucinous cystadenoma
and cystadenocarcinoma account for 60 - 70%
of all mucoceles. Less common causes are
retention cyst, mucosal hyperplasia, carcinoid,
appendicolith, endometriosis, adhesions and
volvulus. The clinical presentation is usually
non-specific with 50% of cases being an
incidental finding at surgery.
We present two rare cases of mucinous
cystadenoma
and
cystadenocarcinoma
respectively, the 1st case, a female patient was
presented by right lower quadrant pain and
right iliac fossa tenderness, the diagnosis was
made by computed tomography (CT)
scanning, she underwent right hemicolectomy
and histopathology result was mucinous
cystadenoma. The diagnosis of the 2nd case, a
________________________________
Corresponding author
Abubaker Abdelrahman Mohammed Elhaj
E-mail: abubaker.elhaj@yahoo.com
male patient was incidental finding in CT
scanning, physical examination revealed firm,
non tender mass at suprapubic and right iliac
fossa
regions,
he
underwent
right
hemicolectomy with en-block resection of the
sigmoid colon and histopathology result was
mucinous adenocarcinoma.
Benign and malignant appendiceal mucocele
may present as an incidental surgical or
radiological finding. Right hemicolectomy for
cases in which the pathological diagnosis has
not been established are recommend.
Introduction
Appendiceal mucocele is a rare, but wellrecognized entity that can mimic several
common clinical syndromes or present as an
incidental surgical or radiological finding. It
has 0.2% to 0.4% prevalence among
appendectomies(1,2). The term mucocele is
widely used in diagnosing both benign and
malignant lesions, but specific criteria are
being proposed for definitive diagnosis and
surgical
management
of
appendiceal
mucocele(3). While some neoplasms with
malignant potential may be treated
definitively by resection, other seemingly
benign lesions must be treated conservatively
due to complications that ensue from
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Sudan Med J 2013 April;49(1)
Case Report
Appendiceal mucocele Abubaker AM Elhaj
peritoneal and cecal inoculation and the
possibility of progression to malignancy(4, 5).
Mucocele can result from mucosal
hyperplasia,
mucinous
cystadenoma,
mucinous cystadenocarcinoma or simple
mucocele due to obstruction of the appendix
base by faecolith. Signs and symptoms occur
in fewer than 50% of cases and are generally
associated with malignancy(3). These include
pain in the right lower abdominal quadrant, an
abdominal mass, weight loss, nausea,
vomiting, change in bowel habits, anemia, and
hematochezia. Depending on the location of
the appendix, other signs may be observed,
such as hematuria. The most dreaded
complication of benign or malignant mucocele
is pseudomyxoma peritonei, which is difficult
to treat surgically or medically. It has an
uncertain prognosis, with a 5-year survival
rate between 53% and 75%(5, 6).
More than half of appendiceal mucoceles are
mucinous cystadenomas, most of which can
be treated by appendectomy alone, with
careful exploratory laparotomy for mucinous
peritoneal
adhesions
typical
of
pseudomyxoma(7). Wide resection of the
appendix, however, is currently the standard
for conservative surgical management of
unspecified appendiceal mucocele.
Reports of Cases
Case 1
A sixty-year-old woman presented with a
constant, dull right lower quadrant pain of 8
days duration, her pain did not radiate and was
not affected by any activity. She reported no
changes in her appetite or bowel habits and
any hematochezia or melena .The patient had
diabetes mellitus for last 2 years controlled by
oral hypoglycemic agents, but she had no
history of surgery.
On physical examination, she was not febrile
and hemodynamically stable. The abdominal
examination was normal except for tenderness
and guarding over the right iliac fossa.
Laboratory analysis was unremarkable.
Computed tomography scanning revealed a
13.4 x 6.1 x 5.6cm cystic lesion with thin
enhancing wall and internal densities seen in
the right iliac fossa consistent with mucocele
of the appendix. The CT scan also showed,
portal vein thrombosis with varicose veins at
porta hepatis (Fig 1).
Fig 1: Axial CT section through ascending colon.
A large tumor is demonstrated (arrow).
The patient underwent laparotomy and right
hemicolectomy. Large appendicular mass
adherent to overlying small bowels was noted.
Exploration of the peritoneum did not show
evidence of malignancy.
Pathological examination of the surgical
specimen revealed a cecum and ascending
colon 22cm long with 14cm of terminal ileum.
The mucosal surface was grossly normal. The
appendix was markedly dilated and measured
17 x7 x 5cm and cut surface showed lumen
distended by thick gelatinous mucus (Fig 2).
Fig 2: Shows mucinous contents upon opening of cyst
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Sudan Med J 2013 April;49(1)
Case Report
Appendiceal mucocele Abubaker AM Elhaj
The tumor was diagnosed on histological
section as mucinous cystadenoma.
The patient postoperative course was
uneventful, and she was discharged home on
postoperative day 7 on warfarin for life as the
cause of portal vein thrombosis was
discovered to be due to protein C deficiency.
Case 2
A 58-year-old man was on regular follow-up
for renal stone, computed tomography for
kidney, ureter and bladder. CT KUB scanning
accidentally found a soft tissue mass
involving the right iliac fossa region indenting
the medial border of the cecum. He gave
history of fresh blood in the stool for 4 days
and mild weight loss. The patient had a
history of left varicocelectomy and
extracorporeal shock wave lithotripsy (ESWL)
for right renal stone. On physical examination,
he was afebrile and hemodynamically stable.
The abdominal examination revealed left
inguinal crease incision, divarication of the
recti muscle and 14 x 10cm lobulated, firm,
non tender mass, at the suprapubic and right
iliac fossa region.
Laboratory analysis was unremarkable.
Computed tomography scanning revealed a 10
x 12cm cystic mass lesion in the right iliac
fossa adherent to bowel loops and specks of
calcification within noted consistent with
mucocele of the appendix or gastro intestinal
tumor e.g. GIST (Fig 3).
Fig 3: CT abdomen & pelvis showing cystic mass
lesion in the right iliac fossa adherent to bowel loops
and specks of calcification within noted (arrow).
Colonoscopy showed normal cecum and
inflamed ulcerated mucosas of the iliocecal
valve and terminal ileum, multiple biopsies
were taken and histopathology examination
interpretated non specific colitis.
The patient underwent laparotomy. A large
mass arising from the cecum invading the
sigmoid colon and adherent to right ureter was
found. Right hemicolectomy with en-block
resection of the adherent loop of sigmoid
colon was done and proximal sigmoid brought
out as hartmann's procedure. Ureter was
identified and freed (Fig 4).
Fig 4: Resected mass with adherent bowel.
Pathological examination of the surgical
specimen revealed cecum and ascending colon
measures 35cm long. The cecum shows
mucinous mass measuring 14cm in maximum
diameter stuck to and penetrating sigmoid.
The appendix was not identified grossly. The
tumor was diagnosed on histological section
as mucinous adenocarcinoma infiltrating the
wall and extending into the serosa. The seven
lymph nodes were examined and the surgical
cut edges were free of neoplasm. The features
were those of mucinous adenocarcinoma of
the appendix.
The patient was discharged home on post
operative day 7. He was readmitted after 10
days with sepsis. Laparotomy and drainage of
intraperitoneal collections were performed.
The patient was discharged home in good
condition on warfarin because he developed
DVT,
and
is
currently
undergoing
chemotherapy.
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Sudan Med J 2013 April;49(1)
Case Report
Appendiceal mucocele Abubaker AM Elhaj
Discussion
Some consider the term mucocele 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(7). 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. Histopathological findings can
confirm whether further tests are needed for
workup of malignancy. If a patient has a
mucinous cystadenoma of the appendix, as
was the case with our first patient, then right
hemicolectomy is curative (except in cases
that are complicated by pseudomyxoma
peritonei).
In a retrospective study of 135 patients with
appendiceal mucocele, 55% were women;
other reports have shown a distinct male
predominance ratio of 4:1(3, 8). Indications for
removal of appendiceal mucocele are evolving
as diagnostic procedures that lead to surgery
for a wide variety of concomitant conditions
improve. Forty percent of patients in the 135patient study went into the operating room
specifically for treatment of symptoms or to
confirm a diagnosis, while the remaining 60%
had their appendiceal mucocele removed on
incidental finding. Although CT scanning is
usually accurate in imaging a fluid-filled
appendix, the appendix was often missed on
CT scans for workup of coexisting conditions.
This may explain the high incidence of
surgical diagnosis for other conditions. Still,
in the workup for a patient's symptoms of
right lower quadrant abdominal pain or a
palpable abdominal mass, CT scanning has
high sensitivity and specificity for detecting
an abnormal appendix. Also CT scanning has
the advantage of allowing precise observation
of the relationship between the lesion and
adjacent organs and any other abnormalities
associated with the mucocele.
Ultrasonography and endoscopy are becoming
the standards for confirming CT findings
before taking the patient to the operating
room. Endoscopic biopsy and pathological
determination can further guide the operative
procedure if hemicolectomy is wanted to be
avoided. In suspected cases of appendiceal
mucocele, fine needle aspiration should be
avoided to preserve integrity of the appendix
and prevent tumor inoculation(1, 6-11).
Although complications from appendiceal
mucocele are minimal, there is evidence that
complications are associated with concomitant
neoplasms, these occurred in about one-third
of patients in the retrospective study and
undoubtedly contributed to the high number
of incidental findings of mucocele. While the
incidence of ovarian and uterine neoplasms
might be explained in part by the high number
of gynaecologic procedures reported, the
association between appendiceal mucocele
and
colonic
neoplasms
is
well(3,12,13)
established
. This additional evidence
makes a strong case for the use of surveillance
colonoscopy and removal of polyps in any
patient with an appendiceal mucocele. Most
investigators agree that the adenomaadenocarcinoma sequence is similar to the
colonic polyp-adenocarcinoma sequence(14).
No cystadenomas smaller than 2cm have been
reported, which suggests that all mucoceles
larger than 2cm should be removed to
eliminate the chance of progression to
malignancy. Furthermore, all patients,
whether they have benign or malignant
appendiceal mucocele, should be evaluated for
pseudomyxoma peritonei. Although the
condition is more common in malignant
appendiceal mucocele (95% occurrence rate
as opposed to 13% in patients with
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Sudan Med J 2013 April;49(1)
Case Report
Appendiceal mucocele Abubaker AM Elhaj
nonmalignant appendiceal mucocele), the
grave consequences of pseudomyxoma
peritonei and the somewhat better prognosis
for patients whose condition is diagnosed and
treated early should challenge the view that
simple surgical resection and careful
exploration for every diagnosed appendiceal
mucocele is sufficient(5).
Appendiceal mucocele presents a challenge to
the surgeon who does not appreciate the effect
of pathological diagnosis on the operative
procedure. Appendectomy alone should be
performed only on mucinous lesions that are
determined to be non-neoplastic after biopsy.
If appendectomy is performed, precautions
should be taken to minimize the risk of
seeding the peritoneal cavity with mucinous
tumour during manipulation.
Some suggested that if distention of the
appendiceal
lumen
is
observed
laparoscopically, suggesting a mucocele as a
possible diagnosis, conversion to open
appendectomy may be the most prudent
surgical judgment because of the increased
risk of rupture and subsequent pseudomyxoma
peritonei(15). However, appendectomy alone?
Whether open or laparoscopic? It does not
guarantee the removal of all neoplastic tissue,
including extensions into surrounding tissues
and lymph nodes(2).
Mucocele of the appendix is uncommon and
the greatest percentage is of the benign
variety. Its incidence is estimated at
0.224%(16). The incidence of malignant
mucocele is one out of 4,300 surgically
removed appendices(17). The association of
malignant
mucocele
with
diffuse
thromboembolic disease is rather interesting
in the experience of the authors, a hitherto
unreported condition. It is well recognized
that a large percentage of cases of carcinoma
of the pancreas is associated with
thromboembolic disease. It is estimated that
approximately 50% of such cases have an
associated thromboembolic condition. They
may occur anywhere in the body and
characteristically wax and wane, giving rise to
a migrating type of phlebitis, (Trousseau
sign). Thromboplastin-like substances are
supposed to be released and are thought to
play a causal role in the genesis of this
phenomenon. A direct causal relationship
between malignant mucocele of the appendix
and thromboembolic disease has not been
completely established; however, it is known
that mucus producing carcinomas, in
particular
pancreatic
carcinomas,
are
associated with an increase of the
antithrombin titer(18-21). As in our 2nd case,
who developed deep vein thrombosis of the
both lower limbs despite of all prophylactic
measures were done (he received clexane
40mg daily, thromboembolic detergent
stockings and early mobilization, but he didn't
checked for thrombogenic diseases).
In conclusion, preoperative diagnosis of
appendicular mucocele is very important for
the selection of an adequate surgical method
to prevent peritoneal dissemination, to prevent
intraoperative and postoperative complication,
and repeated surgery. Ultrasonography,
computed tomography (CT), colonoscopy and
intra-operative frozen sections are used for
diagnostics.
We
recommend
right
hemicolectomy for cases in which the
pathological diagnosis has not been
established and for any cases suspicious for
adenocarcinoma
or
complicated
by
concomitant adenocarcinomatous disease or
pseudomyxoma peritonei.
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