doi:10.1136/gut.2007.129684
2008;57;339-343; originally published online 27 Jul 2007; Gut

Mizukami, N Yanagawa, T Fujii, T Obara, T Okumura and Y Kohgo
S Tanno, Y Nakano, T Nishikawa, K Nakamura, J Sasajima, M Minoguchi, Y


results
without mural nodules: long-term follow-up
papillary-mucinous neoplasms of the pancreas
Natural history of branch duct intraductal
/>Updated information and services can be found at:
These include:
References
/>1 online articles that cite this article can be accessed at:


/>This article cites 31 articles, 3 of which can be accessed free at:
service
Email alerting
the top right corner of the article
Receive free email alerts when new articles cite this article - sign up in the box at
Notes

/>To order reprints of this article go to:
/> go to: GutTo subscribe to
on 11 August 2008 gut.bmj.comDownloaded from
Natural history of branch duct intraductal papillary-
mucinous neoplasms of the pancreas without mural
nodules: long-term follow-up results
S Tanno,

1
Y Nakano,
2
T Nishikawa,
2
K Nakamura,
2
J Sasajima,
2
M Minoguchi,
2
Y Mizukami,
2
N Yanagawa,
2
T Fujii,
2
T Obara,
2
T Okumura,
1
Y Kohgo
2
1
Department of General
Medicine, Asahikawa Medical
College, Asahikawa, Japan;
2
Department of
Gastroenterology and

Hematology/Oncology,
Asahikawa Medical College,
Asahikawa, Japan
Correspondence to:
Dr S Tanno, Department of
General Medicine, Asahikawa
Medical College, 2-1-1-1 East
Midorigaoka, Asahikawa,
Hokkaido, 078-8510, Japan;
tanno1se@asahikawa-med.
ac.jp
Revised 10 June 2007
Accepted 17 July 2007
Published Online First
27 July 2007
ABSTRACT
Background and aim: Although branch duct intraductal
papillary-mucinous neoplasms (IPMNs) of the pancreas
without mural nodules are frequently observed in
asymptomatic subjects, the natural history of these
lesions has never been studied. The aim of this study was
to elucidate the natural history of branch duct IPMNs
without mural nodules.
Methods: Eighty-two patients who had no apparent
mural nodules on initial examination were selected for
follow-up. All subjects underwent examinations by
imaging modalities including endoscopic retrograde
pancreatography, and were followed-up by regular
examinations once or twice a year. Serial changes of the
maximum cystic diameter and the appearance of mural

nodules were studied during the observation periods
ranging from 14 to 148 months (median, 61 months).
Results: Nine (11.0%) of 82 patients exhibited obvious
progression of cystic dilatation (median, 59 months). Of
these nine patients with cystic enlargement, six continued
with regular follow-up examinations. Three cases under-
went surgical resection, and were pathologically diag-
nosed as adenoma in two and borderline in one. Four
patients (4.9%) showed newly developed mural nodules
in dilated branch ducts (median, 105 months).
Histological analysis revealed three cases classified as
adenoma and one as carcinoma in situ. None of the
remaining 69 patients (84.1%) showed any changes in
dilated branch ducts (median, 57 months).
Conclusions: Most branch duct IPMNs without mural
nodules remained unchanged during long-term follow-up.
Although follow-up with careful examination is required to
detect newly developed mural nodules in dilated branch
ducts, branch duct IPMNs without mural nodules can be
followed-up without surgery.
Intraductal papillary-mucinous neoplasm (IPMN) of
the pancreas is a relatively new tumour entity that
has unique clinicopathological features.
1–7
They are
defined as an intraductal papillary growth of
neoplastic columnar cells producing mucin that arise
in the main pancreatic duct or its major branches.
These neoplasms are characterised by variable
biological behaviour and are classified as adenoma,

borderline and carcinoma, the last category including
both in situ and invasive varieties.
8
Although current
thinking is that IPMNs have the potential to be
malignant,
9
it is not known whether all IPMNs have
malignant potential or what the time course of
progression may be.
IPMNs can be subdivided into ‘‘main duct’’ and
‘‘branch duct’’ types depending on the location of
the lesion in the main pancreatic duct or the side
branch, respectively.
810
There are significant differ-
ences in the prevalence of cancer between main
duct IPMNs and branch duct IPMNs, ranging from
57% to 92% and 6% to 46%, respectively.
9 11–15
The
largest published series on patients with main duct
IPMNs showed that approximately 70% are
symptomatic, 60% had carcinoma and 46% had
invasive carcinoma.
9
In contrast to main duct
IPMNs, most branch duct IPMNs are asympto-
matic and it is believed that the risk of malignancy
is low in cystic lesions ,30 mm in size.

14 15
Therefore, the classification of IPMNs has sub-
stantial value in determining the management
strategy for this neoplasm.
The majority of IPMNs are branch duct IPMNs,
which are being diagnosed with increasing fre-
quency. Despite frequent reporting, management
of branch duct IPMNs has been controversial. The
treatment controversy is based on the fact that
IPMNs contain a wide range of histological
findings from apparently benign to overtly malig-
nant, and accurate preoperative prediction of
malignancy is not possible by imaging modalities.
Recently, it has been reported that one of the
acceptable predictive signs of malignancy for
branch duct IPMNs is the presence of mural
nodules or protruding lesions in dilated branch
ducts.
15–20
Therefore, branch duct IPMNs without
mural nodules seem to be less aggressive compared
with those with mural nodules or main duct
IPMNs, and may possibly be followed-up conser-
vatively. However, there is no clear consensus on
how best to manage branch duct IPMNs without
mural nodules. Understanding the natural history
of branch duct IPMNs without mural nodules
would allow us to improve management strategies
for this neoplasm. In this study, the natural history
of branch duct IPMNs without mural nodules

during long-term follow-up was studied prospec-
tively.
METHODS
Patients
Eighty-two consecutive patients with branch duct
IPMNs attending the medical gastroenterological
units of our institution: Department of
Gastroenterology, Asahikawa Medical College,
Asahikawa, between 1990 and the end point of
this study (December 2006), who fulfilled the
diagnotic criteria of branch duct IPMN cited below,
were included in the study.
Pancreatic cancer
Gut 2008;57:339–343. doi:10.1136/gut.2007.129684 339
on 11 August 2008 gut.bmj.comDownloaded from
Diagnosis of branch duct IPMNs was based on the
pathognomonic findings of endoscopic retrograde pancreato-
graphy (ERP)
21
—that is, communication between the cyst and
the main pancreatic duct (MPD), and the presence of mucin, as
indicated by filling defects in the pancreatic duct—and was
confirmed by ERP in all cases at diagnosis of branch duct
IPMNs. To exclude mucinous cystic tumours of the pancreas or
pseudocysts, characteristic findings of imaging studies, a grape-
like multilocular cystic lesion communicating with the MPD
was confirmed by CT scan, magnetic resonance cholangiopan-
creatography (MRCP) and endoscopic ultrasonography (EUS) in
all cases. The maximum diameter of the dilated branch duct and
MPD was measured by EUS. Absence of mural nodules in

dilated branch ducts was diagnosed by EUS in combination
with MRCP and CT. To exclude pancreatic intraepithelial
neoplasia, the size of IPMNs had to be .1 cm.
9
Follow-up
Eighty-two branch duct IPMNs without mural nodules were
selected for follow-up without surgical resection as outpatients.
All followed-up patients gave consent for observation instead of
surgical procedures. Imaging modalities including EUS in
combination with CT scan and/or MRCP were performed once
or twice a year. Serial changes of the maximum cystic diameter
and the appearance of mural nodules were studied during the
observation periods, ranging from 14 to 148 months (median,
61 months). Dilated branch ducts showing changes . 10 mm in
diameter were defined as enlarged or reduced.
Statistical analysis
Statistical significance was analysed by Student t and Fisher
exact x
2
tests. Differences were considered significant when the
p value was ,0.05.
RESULTS
Patient characteristics
The characteristics of 82 branch duct IPMN patients attending
the medical gastroenterological unit of the Asahikawa Medical
College are summarised in table 1. They consisted of 57 men
and 25 women, with a median age of 68 years (range, 40–84
years). Only one case (1.2%) had recurrent pancreatitis; the
remaining patients were asymptomatic. The median size of the
dilated branch duct was 20 mm (range, 11–45 mm) at diagnosis

of branch duct IPMNs. The location of the lesion was 49
(59.8%) in the head and 33 (40.2%) in the body to tail of the
pancreas. The median maximum diameter of the MPD was
3 mm (range, 3–12 mm). The median follow-up period was
61 months (range, 14–148 months). Ten of 82 (12.2%) branch
duct IPMNs had an initial dilated branch duct diameter of
>30 mm, with a median diameter of 30 mm (range, 30–45 mm)
(table 2). Fifty-four (65.9%) of those with branch duct IPMNs
were older than 65 years in age, with a median age of 73 years
(range, 65–84 years). There is no significant association between
age and the initial size of the lesions in branch duct IPMN
patients (p = 0.314).
Clinical outcome of branch duct IPMNs without mural nodules
Table 3 shows the clinical outcome of 82 branch duct IPMNs
without mural nodules during long-term follow-up. Nine
(11.0%) of 82 patients exhibited obvious progression of cystic
dilatation after a median follow-up of 59 months (range, 14–
113 months). There were no patients with a reduction in size of
dilated branch ducts. Four patients (4.9%) showed the
appearance of mural nodules in dilated branch ducts after a
median follow-up of 105 months (range, 45–148 months). None
of the remaining 69 patients (84.1%) showed any changes in
dilated branch ducts after a median follow-up of 57 months
(range, 14–138 months).
The characteristics of nine branch duct IPMNs with increased
size of dilated branch ducts are shown in table 4. The nine cases
consisted of one woman and eight men, with a median age of 74
years (range, 52–81 years) at diagnosis of branch duct IPMNs.
Four (44.4%) of these nine patients had a MPD diameter of
>7 mm. Cystic enlargement was observed between 14 and

113 months (median, 59 months) after the diagnosis of branch
duct IPMNs. Although one patient had recurrent pancreatitis
(patient 9), the remainder were asymptomatic. Of nine patients
with cystic enlargement, six continued with regular follow-up
examinations. Three cases underwent surgical resection and the
IPMNs were pathologically diagnosed as adenoma in two and
borderline in one.
The characteristics of the four patients with branch duct
IPMNs with the appearance of mural nodules in dilated branch
ducts are shown in table 5. They consisted of four men, with a
median age of 62 years (range, 43–74 years) at diagnosis of
branch duct IPMNs. All patients were asymptomatic. One
patient had an MPD diameter of 12 mm (patient 1). Mural
nodules appeared between 45 and 148 months (median,
105 months) after diagnosis of branch duct IPMNs. Median
maximum size of the mural nodules was 6.5 mm (range, 6–
8 mm). All of the patients with newly developed mural nodules
underwent surgical resection. At histological analysis, three
cases were classified as adenoma and one as carcinoma in situ.
Table 6 shows a comparison of various clinical factors
between patients with no cystic changes, with increased size
of dilated branch ducts and with the appearance of mural
nodules. The latest size of dilated branch ducts with the
appearance of mural nodules was significantly larger than those
without cystic changes, but not statistically different from
those with cystic enlargement. The MPD diameter in the
Table 1 Characteristics of the 82 patients with branch duct IPMNs
without mural nodules
Branch duct IPMNs
without mural nodules

(n = 82)
Median age (years) (range) 68 (40–84)
Male:female 57:25
Asymptomatic (%) 81 (98.8%)
Median size of dilated branch duct (mm) (range) 20 (11–45)
Median diameter of MPD (mm) (range) 3 (3–12)
Location (%)
Head 49 (59.8%)
Body–tail 33 (40.2%)
Median follow-up periods (months) (range) 61 (14–148)
IPMN, intraductal papillary-mucinous neoplasm; MPD, main pancreatic duct.
Table 2 Initial size of the dilated branch duct of the pancreas in relation
to age
Initial size of the dilated
branch duct
Age (years)
,65 (%) >65 (%)
,30 mm 26 (92.8) 46 (85.2)
>30 mm 2 (7.2) 8 (14.8)
Total 28 (100) 54 (100)
There is no significant association between age and the initial size of the dilated
branch duct (p = 0.314).
Pancreatic cancer
340 Gut 2008;57:339–343. doi:10.1136/gut.2007.129684
on 11 August 2008 gut.bmj.comDownloaded from
patients without cystic changes was significantly narrower than
those with cystic enlargement or with the appearance of mural
nodules. The time of follow-up in patients with appearance of
mural nodules was significantly longer than those without
cystic changes, but not statistically different from those with

cystic enlargement. There were no significant differences in age,
gender, location or initial size of the dilated branch duct
between patients with cystic size changes and patients with the
appearance of mural nodules.
DISCUSSION
Branch duct IPMN has been increasingly recognised and is now
being diagnosed with increasing frequency. Many of these
patients are elderly and asymptomatic. The majority of these
lesions are believed to be premalignant, and the only curative
treatment is surgical resection.
22
Despite the more frequent
reporting of branch duct IPMN, the natural history of this
disease is not well understood, and a number of controversies
regarding its treatment persist. The majority of branch duct
IPMNs appear to have no apparent mural nodules; however,
little precise information is available on the natural history of
branch duct IPMNs without mural nodules.
Although current thinking is that all IPMNs have the
potential to be malignant,
9
the frequency and rate of progres-
sion to carcinoma in situ and invasive carcinoma are not known
and may be different for branch duct IPMNs with and without
mural nodules. It is clear that branch duct IPMN has a more
favourable prognosis than standard ductal pancreatic adenocar-
cinoma
23
; however, the factors that determine outcome in these
patients are not well understood. This is the first report

demonstrating the evidence that the absence of mural nodules
may be an important factor in determining a conservative
management strategy for this tumour, as most branch duct
IPMNs without mural nodules remained unchanged during
long-term follow-up. Our data emphasise that branch duct
IPMNs without mural nodules can be followed-up with careful
examination to detect newly developed mural nodules in the
dilated branch duct. The advantages of our study include a
prospective study design, a near complete follow-up with a
median of 61 months, and a much larger sample size of branch
duct IPMNs than in previous studies.
24–29
In this study, 69 (84.1%) of 82 branch duct IPMN patients
without mural nodules showed no changes in the dilated branch
duct during follow-up lasting 14–138 months (median,
57 months) after diagnosis of branch duct IPMNs, whereas
progression of branch duct IPMNs was found in 13 patients
(15.9%) during follow-up lasting 14–148 months (median,
67 months). Of 13 patients exhibiting progression of IPMNs,
nine patients (69.2%) had cystic enlargement alone. Three cases
underwent surgical resection and were pathologically diagnosed
as adenoma in two and borderline in one. Of four patients with
newly developed mural nodules who underwent surgical
resection, histological analysis showed that three cases were
classified as adenoma and one as carcinoma in situ. Importantly,
our study demonstrated that there was no invasive carcinoma
in surgically resected specimens of branch duct IPMNs without
mural nodules that had an increase in dilated branch duct size or
the appearance of mural nodules. These findings suggest that
close observation with careful attention to the appearance of

mural nodules or cystic enlargement will obviate unnecessary
surgery. However, the presence of mural nodules should be
considered to be an indication for surgery in order to avoid the
wrong treatment, because mural nodules have been reported to
be indicative of malignancy in branch duct IPMNs,
15–20
and the
natural history of branch duct IPMNs with mural nodules is not
understood.
In the past, several authors have noted that a cyst diameter of
>30 mm suggests malignancy in branch duct IPMNs.
30 31
In this
study, the 82 branch duct IPMN patients without mural
nodules included 10 patients (12.2%) with a cystic size of
>30 mm in diameter. Among them, two patients (20%) showed
cystic enlargement alone and one (10%) had the appearance of a
mural nodule, at 64.9 and 60.3 months on average after
diagnosis of branch duct IPMNs, respectively. At pathological
analysis, two cases were classified as adenoma and one as
borderline. The remaining seven patients (70%) remained
unchanged during the follow-up lasting 21–50 months (median,
30 months). In our experience, therefore, cystic lesions of
>30 mm in diameter did not correlate well with cystic
Table 3 Clinical outcome of branch duct IPMNs without mural nodules
Clinical outcome
Branch duct IPMNs without
mural nodules (%)
Size of dilated branch duct*
No change 69 (84.1)

Reduced 0 (0)
Enlarged 9 (11.0){
Appearance of mural nodules 4 (4.9){
Total 82 (100)
*Branch ducts showing changes .10 mm were defined as enlarged or reduced.
{Three cases underwent surgery; the remaining six cases continued with regular
follow-up examinations only.
{All cases underwent surgery.
IPMN, intraductal papillary-mucinous neoplasm
Table 4 Characteristics of the nine patients with branch duct IPMNs with increased size of the dilated branch duct during follow-up
Patient
number Age* (years) Sex Location
Dilated branch duct
Diameter of
MPD (mm)
Duration of
follow-up
(months) Treatment Histology
Initial size
(mm)
Latest size
(mm)
1 67 M Head 16 35 3 106 Follow-up –
2 74 M Body 15 30 3 59 Follow-up –
3 74 M Head 30 40 10 113 Follow-up –
4 76 M Body–tail 16 26 3 19 Follow-up –
5 76 M Head 20 35 3 92 Follow-up –
6 81 F Head 21 37 3 48 Follow-up –
7 55 M Body 15 25 8 79 DP Adenoma
8 72 M Body 18 28 10 54 DP Adenoma

9 52 M Head 32 45 8 14 PpPD Borderline
*Age at initial diagnosis of branch duct IPMN
DP, distal pancreatectomy; F, female; IPMN, intraductal papillary-mucinous neoplasm; M, male; PpPD, pylorus-preserving pancreaticoduodenectomy.
Pancreatic cancer
Gut 2008;57:339–343. doi:10.1136/gut.2007.129684 341
on 11 August 2008 gut.bmj.comDownloaded from
enlargement or the appearance of mural nodules. A similar
observation was made by Chari et al.
32
In their study, 73 non-
invasive IPMNs had an average diameter of 52 mm, whereas 40
invasive IPMNs had an average diameter of 66 mm. Thus, these
data suggest that the size of a branch duct IPMN alone cannot
be used to determine the treatment strategy.
Several authors reported that a dilated MPD of >7 mm may
predict malignancy of branch duct IPMNs in studies based on
pathological analysis of surgically resected pancreas.
24–27
In this
study, the mean maximum diameter of the MPD in branch duct
IPMNs without cystic size changes was significantly narrower
than those with the appearance of mural nodules or enlarge-
ment of the dilated branch duct. Eleven (13.4%) of 82 patients
had a dilated MPD of >7 mm, and six of these (54.5%) showed
progression of branch duct IPMN during follow-up lasting 14–
148 months (median, 73 months). Furthermore, all three cases
which had a MPD diameter of >10 mm showed cystic
enlargement in two and the appearance of mural nodules in
one. Thus, our follow-up data support the previous reports
24–27

and suggest that a dilated MPD of >7 mm may also predict the
progression of branch duct IPMNs without mural nodules.
In this study, 54 (65.9%) branch duct IPMN patients were 65
years or older. Among them, eight patients (14.8%) showed
cystic enlargement in six and the appearance of mural nodules
in two. Of 28 patients ,64 years old, five patients (17.9%)
showed cystic enlargement in two and appearance of mural
nodules in three. The mean age of those with branch duct
IPMNs without cyst size changes at diagnosis of IPMNs was
not significantly less than those with the appearance of mural
nodules or enlargement of the dilated branch duct. In addition,
the mean follow-up period of branch duct IPMNs without cyst
size changes was not shorter than those with the appearance of
mural nodules or enlargement of the dilated branch duct. Thus,
these data suggest that age may not be a predictive factor for
progression of branch duct IPMNs without mural nodules.
Quality of life must certainly be taken into account in electing
to perform surgery for branch duct IPMNs in elderly patients,
especially with very old patients or those with impairments,
because the operation involves a high level of morbidity.
In conclusion, the current study demonstrated the long-term
follow-up results of branch duct IPMN patients without mural
nodules. The absence of mural nodules supports a conservative
management policy without surgery in branch duct IPMNs,
although follow-up with careful examination is required to
detect the appearance of mural nodules in dilated branch ducts.
It is recommended that careful attention should be paid to the
presence or absence of mural nodules in order to determine the
treatment strategy for branch duct IPMNs.
Competing interests: None.

REFERENCES
1. Loftus EV Jr, Olivares-Pakzad BA, Batts KP, et al. Intraductal papillary-mucinous
tumors of the pancreas: clinicopathologic features, outcome, and nomenclature.
Members of the Pancreas Clinic, and Pancreatic Surgeons of Mayo Clinic.
Gastroenterology 1996;110:1909–18.
2. Azar C, Van de Stadt J, Rickaert F, et al. Intraductal papillary mucinous tumours of
the pancreas. Clinical and therapeutic issues in 32 patients. Gut 1996;39:457–64.
3. Rivera JA, Fernandez-del Castillo C, Pins M, et al. Pancreatic mucinous ductal
ectasia and intraductal papillary neoplasms. A single malignant clinicopathologic
entity. Ann Surg 1997;225:637–44.
4. Morohoshi T, Kanda M, Asanuma K, et al. Intraductal papillary neoplasms of the
pancreas. A clinicopathologic study of six patients. Cancer 1989;64:1329–35.
5. Rickaert F, Cremer M, Deviere J, et al. Intraductal mucin-hypersecreting neoplasms
of the pancreas. A clinicopathologic study of eight patients. Gastroenterology
1991;101:512–9.
6. Yamada M, Kozuka S, Yamao K, et al. Mucin-producing tumor of the pancreas.
Cancer 1991;68:159–68.
7. Obara T, Maguchi H, Saitoh Y, et al. Mucin-producing tumor of the pancreas: a
unique clinical entity. Am J Gastroenterol 1991;86:1619–25.
8. Hruban RH, Takaori K, Klimstra DS, et al. An illustrated consensus on the
classification of pancreatic intraepithelial neoplasia and intraductal papillary mucinous
neoplasms. Am J Surg Pathol 2004;28:977–87.
9. Salvia R, Fernandez-del Castillo C, Bassi C, et al. Main-duct intraductal papillary
mucinous neoplasms of the pancreas: clinical predictors of malignancy and long-term
survival following resection. Ann Surg 2004;239:678–85; discussion 85–7.
10. Tanaka M, Chari S, Adsay V, et al. International consensus guidelines for
management of intraductal papillary mucinous neoplasms and mucinous cystic
neoplasms of the pancreas. Pancreatology 2006;6:17–32.
11. Kobari M, Egawa S, Shibuya K, et al. Intraductal papillary mucinous tumors of the
pancreas comprise 2 clinical subtypes: differences in clinical characteristics and

surgical management. Arch Surg 1999;134:1131–6.
12. Terris B, Ponsot P, Paye F, et al. Intraductal papillary mucinous tumors of the
pancreas confined to secondary ducts show less aggressive pathologic features as
compared with those involving the main pancreatic duct. Am J Surg Pathol
2000;24:1372–7.
13. Doi R, Fujimoto K, Wada M, et al. Surgical management of intraductal papillary
mucinous tumor of the pancreas. Surgery 2002;132:80–5.
14. Matsumoto T, Aramaki M, Yada K, et al. Optimal management of the branch duct
type intraductal papillary mucinous neoplasms of the pancreas. J Clin Gastroenterol
2003;36:261–5.
15. Sugiyama M, Izumisato Y, Abe N, et al. Predictive factors for malignancy in
intraductal papillary-mucinous tumours of the pancreas. Br J Surg 2003;90:1244–9.
16. Yamaguchi K, Ogawa Y, Chijiiwa K, et al. Mucin-hypersecreting tumors of the
pancreas: assessing the grade of malignancy preoperatively. Am J Surg
1996;171:427–31.
17. Sugiyama M, Atomi Y, Hachiya J. Intraductal papillary tumors of the pancreas:
evaluation with magnetic resonance cholangiopancreatography. Am J Gastroenterol
1998;93:156–9.
Table 5 Characteristics of the four patients with branch duct IPMNs with the appearance of mural nodules in the dilated branch duct during follow-up
Patient
number
Age*
(year) Sex Location
Dilated branch duct
Size of mural
nodules (mm)
Diameter of
MPD (mm)
Duration of
follow-up

(months) Treatment Histology
Initial size
(mm)
Latest size
(mm)
1 43 M Head 20 30 7 12 67 PpPD Adenoma
2 61 M Head 15 32 6 5 143 PpPD Carcinoma in situ
3 63 M Tail 20 65 8 9 148 DP Adenoma
4 74 M Body 30 30 6 4 45 DP Adenoma
*Age at initial diagnosis of branch duct IPMN.
DP, distal pancreatectomy; IPMN, intraductal papillary-mucinous neoplasm; M, male; PpPD, pylorus-preserving pancreaticoduodenectomy.
Table 6 Comparison of clinical factors between clinical outcomes
Size of dilated branch duct
Appearance of
mural nodules
(SD)
No change
(SD)
Enlarged
(SD)
Age (years) 67.8 (8.8) 69.7 (9.9) 60.3 (12.8)
Male:female 45:24 8:1 4:0
Dilated branch duct (mm)
Initial size 19.1 (6.7) 20.3 (6.4) 21.3 (6.3)
Latest size 19.2 (6.9)*{ 33.4 (6.7* 39.3 (17.2){
Location (head:body–tail) 42:27 5:4 2:2
Initial diameter of MPD (mm) 3.7 (1.5){1 5.7 (3.2){ 7.5 (3.7)1
Time of follow-up (months) 62.1 (35.7)" 64.9 (35.5) 100.8 (52.5)"
*p,0.001; {p,0.001; {p,0.01; 1p,0.001; "p,0.05.
MPD, main pancreatic duct.

Pancreatic cancer
342 Gut 2008;57:339–343. doi:10.1136/gut.2007.129684
on 11 August 2008 gut.bmj.comDownloaded from
18. Yanagisawa A, Ohashi K, Hori M, et al. Ductectatic-type mucinous cystadenoma
and cystadenocarcinoma of the human pancreas: a novel clinicopathological entity.
Jpn J Cancer Res 1993;84:474–9.
19. Sugiyama M, Atomi Y. Intraductal papillary mucinous tumors of the pancreas:
imaging studies and treatment strategies. Ann Surg 1998;228:685–91.
20. Irie H, Honda H, Aibe H, et al. MR cholangiopancreatographic differentiation of
benign and malignant intraductal mucin-producing tumors of the pancreas.
Am J Roentgenol 2000;174:1403–8.
21. Shyr YM, Su CH, Tsay SH, et al. Mucin-producing neoplasms of the pancreas.
Intraductal papillary and mucinous cystic neoplasms. Ann Surg 1996;223:141–6.
22. Kiely JM, Nakeeb A, Komorowski RA, et al. Cystic pancreatic neoplasms: enucleate
or resect? J Gastrointest Surg 2003;7:890–7.
23. Sohn TA, Yeo CJ, Cameron JL, et al. Intraductal papillary mucinous neoplasms of the
pancreas: an increasingly recognized clinicopathologic entity. Ann Surg 2001;234:313–21.
24. Obara T, Maguchi H, Saitoh Y, et al. Mucin-producing tumor of the pancreas: natural
history and serial pancreatogram changes. Am J Gastroenterol 1993;88:564–9.
25. Irie H, Yoshimitsu K, Aibe H, et al. Natural history of pancreatic intraductal papillary
mucinous tumor of branch duct type: follow-up study by magnetic resonance
cholangiopancreatography. J Comput Assist Tomogr 2004;28:117–22.
26. Wakabayashi T, Kawaura Y, Morimoto H, et al. Clinical management of intraductal
papillary mucinous tumors of the pancreas based on imaging findings. Pancreas
2001;22:370–7.
27. Yamaguchi K, Sugitani A, Chijiiwa K, et al. Intraductal papillary-mucinous tumor of
the pancreas: assessing the grade of malignancy from natural history. Am Surg
2001;67:400–6.
28. Levy P, Jouannaud V, O’Toole D, et al. Natural history of intraductal papillary
mucinous tumors of the pancreas: actuarial risk of malignancy. Clin Gastroenterol

Hepatol 2006;4:460–8.
29. Salvia R, Crippa S, Falconi M, et al. Branch-duct intraductal papillary mucinous
neoplasms of the pancreas: to operate or not to operate? Results of a prospective
protocol on the management of 109 consecutive patients. Gut 2006.
30. Sugiyama M, Atomi Y, Kuroda A. Two types of mucin-producing cystic tumors of
the pancreas: diagnosis and treatment. Surgery 1997;122:617–25.
31. Obara T, Maguchi H, Saitoh Y, et al. [Mucin-producing tumor of the pancreas:
surgery or follow-up?]. Nippon Shokakibyo Gakkai Zasshi 1994;91:66–74.
32. Chari ST, Yadav D, Smyrk TC, et al. Study of recurrence after surgical resection of
intraductal papillary mucinous neoplasm of the pancreas. Gastroenterology
2002;123:1500–7.
Robin Spiller, editor
Double lumen duodenum in a patient
with melaena
CLINICAL PRESENTATION
A previously healthy 40-year-old woman came to our emer-
gency department because of acute epigastric and tarry stools.
Her vital signs were stable, and physical examination did not
disclose other abnormalities. The blood sampling showed a
normal level of haemoglobin and normal coagulation profile.
Panendoscopy was performed under the impression that upper
gastrointestinal haemorrhage was present, and there was no
definite abnormality in the oesophagus and stomach except a
double lumen identified in the second portion of the duodenum
(fig 1).
QUESTION
What is your diagnosis?
See page 364 for answers
K-L Liu,
1

Y-M Tsang,
1
J-T Lin,
2
H-P Wang
3
1
Department of Medical Imaging, National Taiwan University Hospital and National
Taiwan University College of Medicine, Taipei, Taiwan;
2
Department of Internal
Medicine, National Taiwan University Hospital and National Taiwan University College
of Medicine, Taipei, Taiwan;
3
Department of Emergency Medicine, National Taiwan
University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan
Correspondence to: Dr. Hsiu-Po Wang, Department of Emergency Medicine,
National Taiwan University Hospital, No. 7, Chung-Shan South Road, Taipei, Taiwan;

Competing interests: None.
Gut 2008;57:343. doi:10.1136/gut.2006.115311
Figure 1 Panendoscopy shows a double lumen in the second portion of
the duodenum.
Editor’s quiz: GI snapshot
Pancreatic cancer
Gut March 2008 Vol 57 No 3 343
on 11 August 2008 gut.bmj.comDownloaded from