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Mucinous cystic neoplasms of the pancreas: pathology
and molecular genetics.
J
Hepatobiliary Pancreat Surg. 2007;14(3):238-42.
Mucinous cystic neoplasm (MCN) of the pancreas is
a distinct clinicopathological entity characterized by mucin-producing
epithelial and cyst-forming neoplasm with "ovarian-type" stroma
beneath the epithelial component. It is clearly distinguished from
ductal adenocarcinoma and intraductal papillary mucinous neoplasm (IPMN).
However, MCN can progress to infiltrating carcinoma, and frequently
shows a similar histological pattern to ductal adenocarcinoma. Several
genetic alterations such as K-ras oncogene mutation, and epigenetic
alterations such as hypermethylation of p16 in the invasive component
of MCN are also common with ductal adenocarcinoma. Furthermore, recent
technologies, including a laser-assisted microdissection system for
histological slides and global gene expression profilings using DNA
microarrays, made possible to identify more information about
molecular abnormalities of MCNs. It is important to diagnose the
lesions before they progress to an invasive carcinoma. MCN is one of
the precursors of invasive pancreatic carcinoma.
Mucinous cystadenocarcinoma of the pancreas diagnosed in
postpartum.
Langenbecks Arch Surg. 2007 Aug;392(4):493-6.
BACKGROUND: Cystic tumors of the pancreas are
uncommon. They account for 10-15% of all pancreatic cystic masses and
only 1% of pancreatic malignancies. Mucinous cystadenocarcinoma is the
most frequent pancreatic cystadenocarcinoma and it is mainly seen in
women, suggesting a sex hormone influence. Its presentation during
pregnancy is infrequent and entails difficult diagnostic and
therapeutic decisions. We report the case of a 31-year-old woman who
presented a pancreatic cystadenocarcinoma 2 months after delivery.
MATERIALS AND METHODS: A 31-year-old woman was referred to our service
because of abdominal pain and mass. She had given birth to her first
child 2 months previous. Abdominal ultrasound demonstrated a poorly
circumscribed cystic mass in the left upper abdominal quadrant, and
the computed tomography scan showed a multilocular cystic lesion
located in the body of pancreas. There was no seric alteration of
specific pancreatic enzymes or tumor markers. RESULTS: Laparoscopic
examination showed a large cystic tumor (12 x 11 x 5.5 cm) in the
pancreas involving the body and the tail. It extended to the spleen
and was highly vascularized, precluding a minimal invasive resection.
An open body-tail pancreatectomy and splenectomy was performed. The
resection margins were free of tumor, and the histological study
showed a mucinous pancreatic cystadenocarcinoma with mucin-producing
columnar epithelium and associated papillae patterns, reminiscent of
ovarian stroma. Immunohistochemical studies were negative for hormonal
receptors. The patient had no post-surgical complications and was
discharged home in 4 days. CONCLUSIONS: Cystic tumors of the pancreas
are infrequent, and cancer of the pancreas during pregnancy is
extremely rare. Insidious symptoms and bodily changes due to pregnancy
may mask diagnosis. Aggressive surgery is currently the only chance of
cure.
Pancreatic, hepatic, splenic, and mesenteric
mucinous cystic neoplasms (MCN) are lumped together as extra ovarian
MCN.Pathol Int.
2006 Feb;56(2):71-7.
Mucinous cystic neoplasms (MCN) of the pancreas
are mucin-producing cystic tumors with an ovarian-like stroma (OLS).
In the present study MCN were obtained from 27 patients. These MCN
were derived from 22 pancreas, three livers, spleen, and mesentery.
MCN in various organs have common clinicopathological profiles, being
unilocular or multilocular cystic tumors, with a fibrous capsule and
lined by mucin-secreting epithelium associated with an underlying
subepithelial OLS. The OLS showed strong positivity for alpha-smooth
muscle actin (alpha-SMA) and vimentin and weak, focal positivity for
desmin. Both estrogen receptors and progesterone receptors were
expressed in the nuclei of OLS cells. In addition, 20 ovarian MCN and
13 normal ovaries were studied with particular attention to the stroma.
The stroma of ovarian MCN was strongly immunopositive for alpha-SMA
and vimentin and focally positive for desmin, whereas normal ovarian
stroma was immunonegative for both alpha-SMA and desmin. The OLS of
MCN mentioned here was similar to the septa of ovarian MCN but not to
ovarian stroma. In conclusion, MCN in various organs should be lumped
together as 'extra ovarian' MCN. The OLS was identified on the basis
of myofibroblastic proliferation both in response to neoplastic
development and dependent on hormones.
Clinicopathological and immunohistochemical
analysis of malignant features in mucinous cystic tumors of the
pancreas.Hepatogastroenterology .2006 Mar-Apr;53(68):286-90.
BACKGROUND/AIMS: To investigate the malignancy of
mucinous cystic tumors (MCTs) of the pancreas, we examined
clinicopathological features and immunohistochemical findings of MCT.
METHODOLOGY: We analyzed the expression of p53 protein, proliferating
cell nuclear antigen, alpha6-integrin subunit, alpha5beta1-integrin,
and interleukin-1 receptor type I in tumor specimens from eight
patients with MCT. RESULTS: The tumors were classified as mucinous
cyst adenoma (n=6) or mucinous cyst adenocarcinoma (n=2). The
actuarial five-year survival rate was 83.3%. All in eight MCTs had
'ovarian-type' stroma in the cyst wall. The alpha6-integrin subunit
and p53 protein were expressed in adenocarcinoma tissues of MCTs, and
in two adenomas the alpha6-integrin subunit and p53 protein were also
co-expressed. CONCLUSIONS: Our present results indicate that
coexpression of the alpha6-integrin subunit and p53 protein should be
appreciated as an indicator of malignancy in MCTs.
A review of mucinous cystic neoplasms of the
pancreas defined by ovarian-type stroma: clinicopathological features
of 344 patients.World
J Surg. 2006 Dec;30(12):2236-45.
INTRODUCTION: Despite formal definitions of
mucinous cystic neoplasms (MCNs) and intraductal papillary neoplasms (IPMNs)
by the World Health Organization (WHO) and Armed Forces Institute of
Pathology (AFIP), several controversies with regard to MCNs remain.
The aim of this review was to determine the clinicopathological
features of MCNs defined by ovarian-type stroma (OS) as proposed by
the WHO and AFIP and to compare them with MCNs defined by less
stringent criteria. METHODS: A MEDLINE search was conducted to
identify English-language articles on pancreatic MCNs from 1996 to
2005. Twenty-five studies were identified. The studies were divided
into 2 groups: group A included 10 studies with 344 patients whereby
the presence of OS was a criteria for the diagnosis of MCNs, and group
B, included 15 studies comprising 761 patients whereby the presence of
OS was not mandatory for the diagnosis of MCNs. RESULTS: Patients in
group A (MCNs as defined by OS) were almost always female (99.7%),
with a mean age of 47 (range, 18-95) years. MCNs were located
predominantly in the body or tail of the pancreas (94.6%) and had a
mean size of 8.7 cm (range, 0.6-35 cm); 76% were symptomatic, 6.8%
demonstrated ductal communication, and 27% were malignant. At a mean
follow-up of 57.5 (range, 1-264) months and 43 (range, 2-257) months
after surgery, 97.9% of benign and 61.9% of malignant neoplasms were
disease free, respectively. Patients in group B were older and had a
higher proportion of males. Neoplasms were more evenly distributed in
the pancreas, were smaller, communicated more frequently with the
pancreatic duct, and were composed of a higher proportion of malignant
tumors compared with group A. Their clinicopathological features were
intermediate between those of group A and patients with IPMN.
CONCLUSION: Pancreatic MCNs with OS have unique and distinct
clinicopathological features. MCNs should be defined by the presence
of OS, as it is the most reliable way of distinguishing MCNs from IPMN.
Adoption of "looser" criteria will result in misclassification of some
IPMNs as MCNs.
Mucinous cystic tumour of the pancreas. A case
report. Chir Ital.
2006 May-Jun;58(3):367-72.
Although cystic neoplasms and lesions of the
pancreas are rare (5% of exocrine tumours), they have attracted a
great deal of attention because of their potential curability. In
contrast to serous cystic neoplasms, which are generally benign, the
mucinous variant is known to have considerable malignant potential.
Most authorities agree that no imaging technique (US, CT, MRI) is
sufficiently accurate to differentiate between the multiple benign,
premalignant and malignant lesions that can be visualised. We report a
case of a young woman with a mucinous cystic tumour of the pancreas
which was successfully treated surgically and compare our data with
those emerging from a review of the literature. We observed a
26-year-old woman who presented with an abdominal mass and mild
symptoms. CT scan suggested a mucinous cystic neoplasm of the
pancreas. We treated the patient surgically, performing resection of
the neoplasm with left pancreatectomy. The histological examination
revealed a benign pancreatic cystadenoma. Mucinous cystic neoplasms of
the pancreas have a substantial malignant potential and should be
treated surgically with adequate resection margins. Moreover, in our
opinion, even small lesions, especially if symptomatic or present in
older patients, are likely to be malignant and warrant thorough
exploration in patients whose condition permits it.
Rapid growth of mucinous cystic adenoma of the
pancreas following pregnancy.Int
J Gastrointest Cancer. 2006;37(1):45-8.
A 25-yr-old woman delivered a healthy child by
cesarean section. At 8 mo postpartum, she became aware of an upper
abdominal tumor. Abdominal computed tomography and upper abdominal
ultrasonography revealed a large cystic mass in the body of the
pancreas. Endoscopic retrograde pancreatography showed no connection
between the main pancreatic duct and the cystic lesion. The patient
underwent tumor resection at 11 mo postpartum. Pathological
examination of the tumor revealed mucin-producing columnar epithelial
cells lining the cystic wall with ovarian-type stromal tissue and no
findings indicative of malignancy, giving a diagnosis of mucinous
cystic adenoma of the pancreas. Immunohistochemical studies revealed
positive staining for progesterone receptor but not for estrogen
receptor in the stromal cell nuclei. Postpartum rapid growth of a
benign mucinous cystic neoplasm might be linked to the production of
female sex hormones during lactation.
Mucinous cystic tumor of the pancreas:
immunohistochemical assessment of "ovarian-type stroma". Oncol
Rep. 2003 May-Jun;10(3):515-25.
The new histopathological classification of
exocrine pancreatic tumors by the World Health Organization, now
includes "ovarian-type stroma" ("OS") in the definition of mucinous
cystic tumor of the pancreas (MCT-P). This study investigated the
clinicopathological findings of the MCT-P according to WHO
classification and scrutinize the function of "OS" in MCT-P
immunohistochemically. Thirty-four cases of MCT-P (28 adenomas, 2
borderline tumors and 4 adenocarcinomas) were examined
clinicopathologically. The "OS" of 34 MCTs-P were studied
immunohistochemically and compared with the stroma of 10 mucinous
cystic tumors of the ovary (MCTs-O), 10 conventional pancreatic
carcinomas and 6 normal ovaries. Almost all 34 MCTs-P were located in
the body-tail of the pancreas of middle-aged women. Histologically the
"OS" cells exhibited luteinization in 11/34 (32.4%).
Immunohistochemically, both "OS" cells and the stromal cells in MCT-O
showed similar positivity rates; calponin (34/34 and 9/10), h-caldesmon
(28/34 and 8/10), alpha-inhibin (29/34 and 9/10), estrogen-receptor
(21/34 and 6/10) and progesterone-receptor (28/34 and 9/10,
respectively). Some neoplastic epithelial cells of MCT-P were positive
for human chorionic gonadotropin (hCG) (21/34, 61.8%). This study
indicates the predominance of MCT in the distal pancreas of
middle-aged women. Furthermore, the immunohistochemical and
histological results demonstrate that the "OS" of MCT-P and the stroma
of MCT-O share the same characteristics. The results also suggested
that the hCG produced by the neoplastic epithelium probably plays an
important role in the luteinization of the stroma of MCT-P. We
therefore conclude there is a possibility that MCT-P originates from
the left remnant primordial gonadal cells which migrated to the
pancreatic anlage during the early development of the fetus.
Mucinous cystic neoplasm (mucinous cystadenocarcinoma of low-grade
malignant potential) of the pancreas: a clinicopathologic study of 130
cases.Am
J Surg Pathol. 1999 Jan;23(1):1-16.
Mucinous cystic neoplasms (MCNs) of the pancreas
are uncommon tumors. The classification and biologic potential of
these neoplasms remain the subject of controversy. Attempts to
classify these tumors in a similar manner to ovarian MCNs remains
controversial, as even histologically benign-appearing pancreatic MCNs
metastasize and are lethal. One hundred thirty cases of MCNs were
identified in the files of the Endocrine Pathology Tumor Registry of
the Armed Forces Institute of Pathology from the years 1979 to 1993.
The pathologic features, including hematoxylin and eosin staining,
histochemistry, immunohistochemistry (IHC), cell cycle analysis, and
K-ras oncogene determination were reviewed. These findings were
correlated with the clinical follow-up obtained in all cases. There
were 130 women, aged 20-95 years (mean age at the outset, 44.6 years).
The patients had vague abdominal pain, fullness, or abdominal masses.
More than 95% of the tumors were in the pancreatic tail or body and
were predominantly multilocular. The tumors ranged in size from 1.5 to
36 cm in greatest dimension, with the average tumor measuring >10 cm.
A spectrum of histomorphologic changes were present within the same
case and from case to case. A single layer of bland-appearing,
sialomucin-producing columnar epithelium lining the cyst wall would
abruptly change to a complex papillary architecture, with and without
cytologic atypia, and with and without stromal invasion. Ovarian-type
stroma was a characteristic and requisite feature. Focal sclerotic
hyalinization of the stroma was noted. This ovarian-type stroma
reacted with vimentin, smooth muscle actin, progesterone, or estrogen
receptors by IHC analysis. There was no specific or unique epithelial
IHC. K-ras mutations by sequence analysis were wild type in all 52
cases tested. Ninety percent of patients were alive or had died
without evidence of disease (average follow-up 9.5 years),
irrespective of histologic appearance; 3.8% were alive with recurrent
disease (average 10 years after diagnosis); and 6.2% died of
disseminated disease (average 2.5 years from diagnosis). Irrespective
of the histologic appearance of the epithelial component, with or
without stromal invasion, pancreatic MCNs should all be considered as
mucinous cystadenocarcinomas of low-grade malignant potential.
Pancreatic MCNs cannot be reliably or reproducibly separated into
benign, borderline, or malignant categories.
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