DOI:10.2214/AJR.05.0569
AJR 2006; 187:W178-W186
© American Roentgen Ray Society
Solid Pseudopapillary Tumor of the Pancreas: Typical and Atypical Manifestations
Jin-Young Choi1,2,3,
Myeong-Jin Kim1,2,4,5,
Joo Hee Kim1,2,
Seung Hyoung Kim1,2,
Joon Sok Lim1,2,
Young Taik Oh1,2,
Jae-Joon Chung1,2,
Hyung Sik Yoo1,2,
Jong Tae Lee1,2 and
Ki Whang Kim1,2
1 Department of Diagnostic Radiology, Yonsei University College of Medicine,
Seodaemun-ku Shinchon-dong 134, Seoul 120-752, Korea.
2 Research Institute of Radiological Science, Yonsei University College of
Medicine, Seoul 120-752, Korea.
3 Department of Radiology and Institute of Radiation Medicine, Seoul National
University Hospital, Seoul, Korea.
4 Brain Korea 21 Project for Medical Science, Yonsei University College of
Medicine, Seoul 120-752, Korea.
5 Institute of Gastroenterology, Yonsei University College of Medicine, Seoul
120-752, Korea.
Received April 1, 2005;
accepted after revision June 7, 2005.
Address correspondence to M.-J. Kim
(kimnex{at}yumc.yonsei.ac.kr).
WEB This is a Web exclusive article.
Abstract
OBJECTIVE. The purpose of this pictorial essay is to illustrate the
various appearances of solid pseudopapillary tumor of the pancreas.
CONCLUSION. Solid pseudopapillary tumor of the pancreas is a rare
neoplasm usually found in young women. Typical solid pseudopapillary tumor is
characterized by a well-encapsulated mass with varying amounts of intratumoral
hemorrhage. However, the tumor can have an atypical appearance, such as
metastasis, ductal obstruction, parenchymal and extracapsular invasion,
simulation of islet cell tumor, intratumoral calcification, and occurrence in
a male patient. The typical and atypical manifestations of solid
pseudopapillary tumor can be visualized with cross-sectional imaging.
Keywords: CT • MRI • pancreas • pancreatic neoplasms
Introduction
Solid pseudopapillary tumor is an uncommon neoplasm that mainly occurs in
women in the second to fourth decades of life. It is characterized by low
potential for malignancy and a favorable prognosis. Since Franz
[1] described this tumor in
1959 as a "papillary tumor of the pancreas, benign or malignant,"
the number of reported cases has increased. Synonyms include solid and cystic
tumor, solid and papillary epithelial neoplasm, papillary-cystic neoplasm,
papillary cystic epithelial neoplasm, papillary-cystic tumor, and Franz tumor
[2]. In 1996, the World Health
Organization renamed this tumor solid pseudopapillary tumor for the
international histologic classification of tumor of the exocrine pancreas
[2]. Pathologic examination
reveals that solid pseudopapillary tumor is usually a large, encapsulated mass
composed of a mixture of cystic, solid, and hemorrhagic components. Both a
capsule and intratumoral hemorrhage are important clues to the diagnosis
because these features are rarely found in other pancreatic neoplasms
[3]. However, various atypical
features of solid pseudopapillary tumor are found on cross-sectional imaging.
In this pictorial essay, we illustrate the various appearances of solid
pseudopapillary tumors.
View larger version (119K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2A —20-year-old woman with palpable abdominal mass of solid
pseudopapillary tumor. Axial T1-weighted gradient-echo image shows
well-defined heterogeneous hyperintense mass with rim of low signal intensity
(arrow) in head of pancreas.
|
|
View larger version (117K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2B —20-year-old woman with palpable abdominal mass of solid
pseudopapillary tumor. Axial fast spin-echo T2-weighted image shows
heterogeneous hyperintense mass in head of pancreas. Fibrous capsule appears
as band of low signal intensity (arrow).
|
|
View larger version (106K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2C —20-year-old woman with palpable abdominal mass of solid
pseudopapillary tumor. Unenhanced axial T1-weighted gradient-echo image shows
hemorrhage as area of high signal intensity (arrow).
|
|
View larger version (112K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2D —20-year-old woman with palpable abdominal mass of solid
pseudopapillary tumor. Delayed phase axial T1-weighted gradient-echo image
obtained after gadolinium administration shows heterogeneous enhancement
(arrow) of solid portion of mass.
|
|
Typical Appearance of Solid Pseudopapillary Tumor
The classic CT features of solid pseudopapillary tumor are a large
well-encapsulated mass with varying solid and cystic components caused by
hemorrhagic degeneration (Fig.
1) [4].
Calcifications and enhancing solid areas may be present at the periphery of
the mass. MRI typically shows a well-defined lesion with a mix of high and low
signal intensity on T1- and T2-weighted images (Figs.
2A,
2B,
2C, and
2D). Areas of high signal
intensity on T1-weighted images and low or inhomogeneous signal intensity on
T2-weighted images can help identify blood products and may help in
differentiation of solid pseudopapillary tumor from other pancreatic tumors
[2]. T2-weighted images show a
thick fibrous capsule, which is seen as a discontinuous rim of low signal
intensity. Gadolinium-enhanced dynamic MRI shows early peripheral
heterogeneous enhancement of the solid portion with progressive fill-in
[3].
Atypical Appearances of Solid Pseudopapillary Tumor
Pancreatic Solid Pseudopapillary Tumor with Metastasis to the Liver
Solid pseudopapillary tumor has been reported as a neoplasm with low
potential for malignancy. Metastasis occurs in a small number of cases, the
most common site being the liver. The mass may also have complex features
similar to those of a primary tumor of the pancreas (Figs.
3A,
3B,
3C,
3D,
3E, and
3F). Liver metastatic lesions
can be multiple (Figs. 4A and
4B) but are generally solitary
and may be amenable to resection
[5]. Rare cases of lymph node
metastasis, peritoneal spread, and multiplicity have been reported. A good
prognosis is expected after surgical resection of the primary tumor, even in
the presence of residual metastasis. Cross-sectional imaging is helpful in the
evaluation of liver metastasis to visualize local invasion of surrounding
organs and blood vessels.
View larger version (100K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3A —28-year-old woman with intermittent abdominal pain for 2
months and pancreatic and cystic mass in liver. Surgical resection of liver
confirmed presence of metastatic solid pseudopapillary tumor.
Contrast-enhanced CT scan shows mass (white arrow) in tail of
pancreas with peripheral calcification (black arrow).
|
|
View larger version (96K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3B —28-year-old woman with intermittent abdominal pain for 2
months and pancreatic and cystic mass in liver. Surgical resection of liver
confirmed presence of metastatic solid pseudopapillary tumor. CT scan shows
cystic mass (arrow) with focal solid portion in liver.
|
|
View larger version (100K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3C —28-year-old woman with intermittent abdominal pain for 2
months and pancreatic and cystic mass in liver. Surgical resection of liver
confirmed presence of metastatic solid pseudopapillary tumor. Fast spin-echo
T2-weighted image shows fluid-fluid level within mass (arrow),
indicating hemorrhage.
|
|
View larger version (112K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3D —28-year-old woman with intermittent abdominal pain for 2
months and pancreatic and cystic mass in liver. Surgical resection of liver
confirmed presence of metastatic solid pseudopapillary tumor. Delayed contrast
MR image reveals encapsulation of mass (arrow).
|
|
View larger version (94K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3E —28-year-old woman with intermittent abdominal pain for 2
months and pancreatic and cystic mass in liver. Surgical resection of liver
confirmed presence of metastatic solid pseudopapillary tumor. Delayed MR image
of liver shows cystic mass (arrow) with focal solid component.
Differential diagnoses of cystic metastasis and biliary cystadenoma were
considered.
|
|
View larger version (101K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3F —28-year-old woman with intermittent abdominal pain for 2
months and pancreatic and cystic mass in liver. Surgical resection of liver
confirmed presence of metastatic solid pseudopapillary tumor. Fast spin-echo
T2-weighted image of liver shows well-marginated, hemorrhagic, cystic and
solid mass (arrow).
|
|
View larger version (109K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 4A —56-year-old woman with elevated aspartate aminotransferase
and alanine aminotransferase levels. Axial T1-weighted MR image shows
heterogeneous mass (arrow) in pancreatic tail with areas of high
signal intensity suggesting hemorrhage.
|
|
View larger version (148K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 4B —56-year-old woman with elevated aspartate aminotransferase
and alanine aminotransferase levels. Coronal T2-weighted MR image shows
well-marginated mass (large arrow) arising from tail of pancreas.
Multiple hepatic metastatic lesions (small arrows) are evident.
|
|
View larger version (115K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 5B —43-year-old woman with dyspepsia and solid pseudopapillary
tumor with ductal obstruction. Axial CT scan of pancreas obtained in arterial
phase reveals ill-defined low-density mass (arrow) in head of
pancreas. Focal calcification is present within mass.
|
|
Solid Pseudopapillary Tumor with Ductal Obstruction
Ductal obstruction and secondary pseudocyst formation are rarely seen in
solid pseudopapillary tumors. Their presence in elderly patients may prompt a
provisional diagnosis of ductal cell carcinoma (Figs.
5A,
5B,
5C, and
5D). Smaller solid
pseudopapillary tumors are less sharply circumscribed and often appear
unencapsulated. In addition, smaller tumors are less likely to show prominent
cystic change and often appear as soft tumors with variable amounts of
fibrosis [6].
View larger version (103K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 5D (continued)—43-year-old woman with dyspepsia and solid
pseudopapillary tumor with ductal obstruction. Photograph of surgical specimen
shows infiltrative solid mass (arrow) in head of pancreas. Pancreatic
duct was occluded by solid mass, and upstream pancreatic duct was dilated.
|
|
Solid Pseudopapillary Tumor with Extracapsular Invasion
Solid pseudopapillary tumor infrequently invades a capsule and the
surrounding structures, mainly the spleen, portal vein, and duodenum. Several
features, such as old age, invasion into a capsule or adjacent normal
pancreatic parenchyma, and both vascular and perineural invasion, are
associated with an increase in potential for malignancy (Figs.
6A,
6B,
6C,
6D, and
6E)
[7]. Multiplanar
cross-sectional images can be helpful in the evaluation of pancreatic
parenchymal invasion, its relation to vascular structures, and adjacent organ
invasion.
View larger version (96K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 6A —42-year-old woman with pancreatic mass found incidentally on
imaging. Axial CT scan of pancreas shows encapsulated mass with peripheral
calcification and focal extracapsular extension (arrow).
|
|
View larger version (130K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 6D (continued)— 42-year-old woman with pancreatic mass found
incidentally on imaging. Axial T1-weighted gradient-echo image obtained in
delayed phase of enhancement shows extracapsular extension (arrow) of
tumor.
|
|
Solid Pseudopapillary Tumor Simulating Nonfunctioning Islet Cell Tumor
Solid pseudopapillary tumors sometimes are indistinguishable from
nonfunctioning islet cell tumors. The two types of tumor have similar
features, such as hypervascularity, cystic change, and a well-defined border
without desmoplastic reaction. The cystic components of nonfunctioning islet
cell tumors are moderately increased signal intensity on T1-weighted images
and increased signal intensity on T2-weighted images, whereas cystic portions
of solid pseudopapillary tumors have high signal intensity on T1- and
T2-weighted images, reflecting blood products
[3]. In some instances, areas
of high signal intensity on T1-weighted images and low or inhomogeneous signal
intensity on T2-weighted images of solid pseudopapillary tumors can help
identify the variable stages of hemorrhage
[2]. Moreover, the peripheral
portions of solid pseudopapillary tumors do not show the hypervascularity
typical of nonfunctioning islet cell tumors. However, solid pseudopapillary
tumors with a minimal cystic component or intratumoral hemorrhage are
difficult to differentiate from nonfunctioning islet cell tumor (Figs.
7A,
7B, and
7C). Nonfunctioning islet cell
tumor is found more often in elderly patients and has no female predominance,
as solid pseudopapillary tumor does.
Solid Pseudopapillary Tumor with Dense Calcification
Although it is rare in solid pseudopapillary tumor
[4], peripheral curvilinear
calcification is sometimes seen on radiographs and CT scans (Figs.
8A,
8B,
8C, and
8D). Central, stippled,
eggshell calcifications have been reported
[5]. Cystic pancreatic
neoplasms such as serous cystadenoma and mucinous cystic neoplasm may have
calcification. Mucinous cystic neoplasms may develop peripheral curvilinear
wall calcification, and serous cystadenomas may have central calcification
within the central fibrous scar. However, pancreatic cystic tumors, other than
solid pseudopapillary tumor, rarely have prominent, extensive calcification
(Figs. 9A and
9B).
Solid Pseudopapillary Tumor in Male Patients
Solid pseudopapillary tumors in men may present a diagnostic problem
because they are most commonly seen in young women. The male to female ratio
is 1:9.5 [6]. It has been
reported that sex hormones play a role in the growth of solid pseudopapillary
tumors and that pregnancy is associated with stimulating tumor growth
[8]. Although solid
pseudopapillary tumors rarely occur in men, the images are similar to those in
women (Figs. 10A,
10B, and
10C)
[9]. Solid pseudopapillary
tumors should be the differential diagnostic consideration of a pancreatic
mass with encapsulation and cystic and solid components, even in men.
Conclusion
A subset of pancreatic solid pseudopapillary tumors do not show the classic
findings that are well known to radiologists. Knowledge of the spectrum of
variable features observed in solid pseudopapillary tumor is useful for
differentiating this lesion from other pancreatic neoplasms and in formulating
the correct diagnosis.
References
- Franz VK. Tumors of the pancreas. In: Atlas of tumor
pathology: fasc 27-28, ser 7. Washington, DC: Armed Forces
Institute of Pathology, 1959:32
-33
- Coleman KM, Doherty MC, Bigler SA. Solidpseudopapillary tumor of
the pancreas. RadioGraphics 2003;23
: 1644-1648[Free Full Text]
- Cantisani V, Mortele KJ, Levy A, et al. MR imaging features of
solid pseudopapillary tumor of the pancreas in adult and pediatric patients.
AJR 2003; 181:395
-401[Abstract/Free Full Text]
- Buetow PC, Buck JL, Pantongrag-Brown L, Beck KG, Ros PR, Adair CF.
Solid and papillary epithelial neoplasm of the pancreas: imaging-pathologic
correlation on 56 cases. Radiology 1996;199
: 707-711[Abstract/Free Full Text]
- Choi BI, Kim KW, Han MC, Kim YI, Kim CW. Solid and papillary
epithelial neoplasms of the pancreas: CT findings.
Radiology 1988;166
: 413-416[Abstract/Free Full Text]
- Klimstra DS, Wenig BM, Heffess CS. Solidpseudopapillary tumor of
the pancreas: a typically cystic carcinoma of low malignant potential.
Semin Diagn Pathol 2000;17
: 66-80[Medline]
- Nishihara K, Nagoshi M, Tsuneyoshi M, Yamaguchi K, Hayashi I.
Papillary cystic tumors of the pancreas: assessment of their malignant
potential. Cancer 1993;71
: 82-92[CrossRef][Medline]
- Canzonieri V, Berretta M, Buonadonna A, et al. Solid
pseudopapillary tumour of the pancreas. Lancet Oncol2003; 4:255
-256[CrossRef][Medline]
- Mancini GJ, Dudrick PS, Grindstaff AD, Bell JL. Solid
pseudopapillary tumor of the pancreas: two cases in male patients.
Am Surg 2004; 70:29
-31[Medline]
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
Top
Abstract
Introduction
