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solid pseudopapillary tumor ( spt ) of the pancreas is a rare pancreatic neoplasm with uncertain etiology that usually occurs in young females . since frantz first described spt in 1959
there have been several synonyms for spt in the literature , such as franz 's tumor , solid and cystic tumor , solid and papillary epithelial neoplasm , papillary - cystic neoplasm , papillary cystic epithelial neoplasm and papillary - cystic tumor . in 1996 , the world health organization ( who ) renamed this tumor as spt in the international histological classification of tumors .
solid pseudopapillary tumor is generally considered to have a low potential for malignancy , which is often localized in the pancreas and is rarely a metastatic disease .
because of its rareness and unusual behavior , spt is often associated with diagnostic and therapeutic challenges .
surgical resection is now considered the most efficient treatment option for patients with spt , because it offers a good chance of long - term survival . however , there is a lack of data on the management of liver metastasis in patients with spt .
we report a case of a patient with pancreatic spt with liver metastasis , who obtained a favorable outcome after rigorous treatment .
a 19-year - old female was admitted to our hospital in january 2009 with chief complaints of epigastric mass on palpation for 16 months and upper abdominal pain for 2 months .
findings of routine laboratory tests , including carcinoembryonic antigen ( cea ) and cancer antigen 19 - 9 ( ca 19 - 9 ) , were within the normal range .
an abdominal ct scan found a giant solid mass ( 14.8 cm  8.9 cm ) in the pancreatic body , multiple nodules in the anterior and posterior segment of the right lobe of the liver about 8.5 cm  3.7 cm and 7.2 cm  3.1 cm and splenomegaly ( fig .
subsequently , we performed percutaneous ct - guided tru - cut biopsy of the tumor and pathological diagnosis of the biopsy material revealed pancreatic spt . abdominal ct scan on admission revealed a giant solid mass ( 14.8 cm  8.9 cm ) in the pancreatic body , multiple nodules in the anterior and posterior segment of right lobe of liver about 8.5 cm  3.7 cm and 7.2 cm  3.1 cm and splenomegaly .
a ) unenhanced ct ; b ) early phase of contrast - enhanced ct ; c ) portal phase of contrast - enhanced ct given the patient 's young age as well as the location of the pancreatic tumor , which was not situated in the tail but in the body , pancreaticoduodenectomy apart from distal pancreatectomy , hepatic tumor resection and splenectomy was conducted .
a large mass in the pancreas with multiple metastatic nodules in the liver was seen during the operation .
her post - operative course was unremarkable , and she was discharged 1 week after her surgery with routine follow - ups .
when dissecting the mass , we found a heterogeneous solid appearance with areas of hemorrhage and extensive necrosis .
microscopically , solid areas mainly consisting of monomorphic epithelioid cells and a moderate cellular atypia without mitotic activity were found ( fig .
2 ) . characteristic pseudopapillary formations were frequently observed in the liver metastases ( fig .
immunohistochemical studies of the primary lesion revealed that the tumor cells were diffusely positive for vimentin , neuron - specific enolase ( nse ) , synaptophysin , and cd10 , with less than 20% ki67 proliferation index .
a ) low magnification ( 100 ) ; b ) high magnification ( 400 ) .
he microscopic image of tumor showing the presence of pseudopapillary formations in the liver metastases .
a ) low magnification ( 100 ) ; b ) high magnification ( 400 ) .
ct scan performed 3 months after the surgery showed a metastatic mass in the medial segment of the left lobe of the liver with a size of 5 cm  3 cm ( fig .
radical excision of the metastatic nodules was considered unfeasible , and transcatheter arterial chemoembolization ( tace ) with epirubicin and iodized oil was performed 3 times in total .
adjuvant chemotherapy or radiotherapy were not offered , because very few reports regarding the use of such therapies for pancreatic spt existed with only limited response [ 3 , 4 ] .
and then , follow - up abdominal and chest ct scans were done every 3 months in the first half year and every 6 months afterwards , and no tumor in the pancreas or in the liver was detected
. the patient remained disease - free at 35 months after tace , i.e. 38 months after removal of the primary pancreatic tumor .
three months after the surgery , ct revealed a metastatic mass in the medial segment of the left lobe of liver with a size of 5 cm  3 cm .
a ) unenhanced ct ; b ) early phase of contrastenhanced ct ; c ) portal phase of contrast - enhanced ct
solid pseudopapillary tumor is a rare and indolent neoplasm of the pancreas with a favorable prognosis after resection .
it usually occurs in young women in the second or third decade of life , with an average female : male ratio of 5 : 1.9 , which is up to 10 : 1 in certain studies .
the tendency of spn to afflict predominantly young women leads to the hypothesis that its pathogenesis may be influenced by sex hormones .
yeh et al . have reported that the progesterone receptor is uniquely expressed in spt while both estrogen and progesterone receptors are expressed in mucinous cystic neoplasm .
tien et al . reported no significant differences in qualitative sex hormone receptor status between male and female spt patients .
clinical studies have shown that the progesterone receptor is expressed in all cases of spt . and in our report , the patient tested negative for both estrogen and progesterone receptors .
thus , more evidence has to be collected to clarify the potential impact of sex hormones on the pathogenesis of spt .
immunohistochemical stains show a variety of expressions , such as epithelial , neural and stromal elements .
a previous study hypothesized that it might be a tumor derived from the pancreatic duct cells , acinar cells , and endocrine cells .
recent evidence indicates that spt may arise from the centroacinar cell of the pancreas . based on both immunohistochemical staining and electron microscopic findings ,
a potential link between tumor cells and centroacinar cells is identified . however , further studies are still needed to confirm this correlation . like solid variant of serous cystadenoma of the pancreas , a rare tumor of the pancreas ,
there often has been a delay in diagnosis until the discovery of a large tumor mass during abdominal examination or imaging .
it appears to be capable of local invasion but usually does not metastasize to distant sites .
some studies observed that metastases or tumor recurrence were detected in about 15% of cases of spt .
other sites that may have metastatic masses include the vena cava , spleen , peritoneum and duodenum . in our report
, ultrasonography and ct revealed a large mass in the pancreatic body and multiple nodules in the liver when the patient was admitted to the hospital .
after complete resection of these tumors , liver metastases appeared again 3 months following the surgery , indicating malignancy of the tumor .
generally speaking , surgery is the best choice of treatment even in cases of distant metastasis , because other adjuvant therapies have not shown demonstrable responses .
distal pancreatectomy combined with or without splenectomy can be performed for pancreatic body and/or tail tumor , and pancreatoduodenectomy for pancreatic head tumor .
considering the multiple liver metastases in this case , we performed aggressive surgical resection to remove spt , spleen and liver nodules .
the patient received tace treatment and she remained disease - free at 35 months after tace .
follow - up ct scans did not detect any nodes in the liver after tace .
our report suggests that although pancreatic spt may be associated with malignant potentiality , a favorable prognosis can also be obtained via rigorous treatment .
tace with pharmorubicin and iodized oil is an effective treatment option for the control of liver metastasis of spt .
solid pseudopapillary tumor of the pancreas is a rare pancreatic neoplasm that typically occurs in young females . as a low - grade malignancy , the tumor seldom recurs and metastasizes . 
 management of liver metastasis from such a tumor remains unclear . 
 we present a case of a young girl with liver metastasis due to solid pseudopapillary tumor of the pancreas . 
 she was admitted with chief complaints of epigastric mass on palpation for 16 months and upper abdominal pain for 2 months . 
 an abdominal ct scan detected a mass in the pancreas and multiple nodules in the liver . 
 then , percutaneous ct - guided tru - cut biopsy was performed and pathological diagnosis of the biopsy material revealed solid pseudopapillary tumor of the pancreas . at 3 months after surgical resection of the pancreatic and liver tumors , 
 ct scan found nodules in her liver . 
 the patient received treatment with transcatheter arterial chemoembolization . 
 she remained well during the 3 years of follow - up with no evidence of recurrence . 
 therefore , it is suggested that although solid pseudopapillary tumor of the pancreas may be associated with malignant potentiality , a favorable prognosis can also be obtained via rigorous treatment .