Solid Pseudopapillary Tumor 胰腺

Fig. 1d
Fig. 1e
(d, e,f) Dynamic contrast-enhanced MR scans revealed the early peripheral enhancement with progressively fill in and delayed enhancement of the capsule.
Solid Pseudopapillary Tumor
Typical Solid Pseudopapillary Tumor
Solid pseudopapillary tumor of the pancreas is a rare neoplasm usually found in young women(2040). 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.
Typical 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].
Fig. 1b
Fig. 1c
Fig. 1.—23-year-old woman with a typical solid pseudopapillary tumor of pancreas (b, c) T2 weighted image and T1 weighted image with fat suppression showed the typical imaging features: the capsule, cystic degeneration and hemorrhagic areas.
Fig. 1f
Atypical 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 (Fig. 3). Liver metastatic lesions can be multiple (Fig. 4) 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. Crosssectional imaging is helpful in the evaluation of liver metastasis to visualize local invasion of surrounding organs and blood vessels.
Typical Solid Pseudopapillary Tumor
20-year-old woman with palpable abdominal mass of solid pseudopapillary tumor. A, Axial T1-weighted gradient-echo image shows well-defined heterogeneous hyperintense mass with rim of low signal intensity (arrow) in head of pancreas. B, 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). C, Unenhanced axial T1-weighted gradient-echo image shows hemorrhage as area of high signal intensity (arrow). D, Delayed phase axial T1-weighted gradient-echo image obtained after gadolinium administration shows heterogeneous enhancement (arrow) of solid portion of mass.
Fig. 1.—23-year-old woman with a typical solid pseudopapillary tumor of pancreas
Fig. 1a
(a) Photograph of gross surgical specimen demonstrates the fibrous capsule, hemorrhagic areas and cystic degeneration.
Atypical Solid Pseudopapillary Tumor
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 (Fig. 5). Smaller solid pseudopapillary tumors are less sharply circumscribed and often appear unencapsulated. In addition, smaller tumors are less likely to show proBaidu Nhomakorabeainent cystic change and often appear as soft tumors with variable amounts of fibrosis [6].
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 (Fig. 2). 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 Solid Pseudopapillary Tumor
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. A, Contrast-enhanced CT scan shows mass (white arrow) in tail of pancreas with peripheral calcification (black arrow). B, CT scan shows cystic mass (arrow) with focal solid portion in liver. C, Fast spin-echo T2-weighted image shows fluid–fluid level within mass (arrow), indicating hemorrhage. D, Delayed contrast MR image reveals encapsulation of mass (arrow). E, Delayed MR image of liver shows cystic mass (arrow) with focal solid component. Differential diagnoses of cystic metastasis and biliary cystadenoma were considered. F, Fast spin-echo T2-weighted image of liver shows well-marginated, hemorrhagic, cystic and solid mass (arrow).