Diagnostic Ultrasound - Abdomen and Pelvis

Solid Pseudopapillary Neoplasm
TERMINOLOGY
Abbreviations
• Solid pseudopapillary neoplasm (SPN)
Synonyms
• Solid and papillary epithelial neoplasm (SPEN); papillary
cystic epithelial neoplasm; papillary cystic tumor; solid and
cystic tumor of pancreas, Franz or Hamoudi tumor
Definitions
• Epithelial tumor of exocrine pancreas with low-grade
malignant potential and solid and cystic features
IMAGING
General Features
• Best diagnostic clue
○ Large, encapsulated, round, complex cystic pancreatic
mass with no associated ductal dilatation
• Location
○ Commonly in pancreatic tail
• Size
○ Usually large (average: 10 cm; range: 2.5-20 cm)
• Morphology
○ Typically well-defined, large, solid and cystic mass
○ Lesions < 3 cm show solid, homogeneous appearance
○ May contain dystrophic calcifications
○ Aggressive features are uncommon, but can be seen
– Perivascular invasion, ductal dilation; metastases
usually to liver, but also lymph nodes and peritoneum
Ultrasonographic Findings
• Well-defined, heterogeneous mass with solid and cystic
components
○ Hypoechoic center due to tumor necrosis/hemorrhage
○ Cystic portion may show fluid-debris level
• Color Doppler: Hypovascular, due to areas of necrosis
• Endoscopic ultrasound (EUS): More sensitive for small mass
○ Can guide fine-needle aspiration biopsy
CT Findings
• Heterogeneous density with mixed solid/cystic areas
• Enhancing capsule and soft tissue projections
• Hyperdensity on unenhanced CT from hemorrhage; low
attenuation from nonenhancing areas of necrosis
MR Findings
• Well-demarcated mass with central areas of
heterogeneously bright T1 and T2 signal
○ Low T1 SI: Capsule and solid components that enhance
on post-contrast T1WI
○ High T1 SI: Intratumoral hemorrhage
○ High T2 signal: Necrosis and hemorrhage
○ Low T2 signal: Thick fibrous capsule
Imaging Recommendations
• Best imaging tool
○ Multiplanar CECT or MR
• Protocol advice
○ Unenhanced CT and MR can best demonstrate
intratumoral hemorrhage
○ Post-contrast imaging should include arterial phase
DIFFERENTIAL DIAGNOSIS
Mucinous Cystic Pancreatic Tumor
• No hemorrhage; commonly seen in middle-aged women
Nonfunctioning Neuroendocrine Tumor
• Cystic components typically do not show T1 hyperintensity;
peripheral portions are more hypervascular
Pancreatic Serous Cystadenoma
• No large solid component; usually located in head of
pancreas; more common in elderly women
Pancreatic Ductal Carcinoma
• Rarely necrotic or hemorrhagic; typically shows pancreatic
&/or common bile duct obstruction; older adults
PATHOLOGY
General Features
• Large solitary tumor with variable mixture of solid,
hemorrhagic, and necrotic components
• Low malignant potential
Gross Pathologic & Surgical Features
• Thick, fibrous, hypervascular capsule surrounding soft
tumor, usually with no mass effect/ductal obstruction
Microscopic Features
• Solid nests of homogeneous, epithelioid cells with areas of
separation into pseudopapillary aggregates due to
degeneration
CLINICAL ISSUES
Presentation
• Usually asymptomatic or nonspecific abdominal pain
• May have palpable abdominal mass
Demographics
• ~ 90% female; < 35 years of age
• African Americans or non-Caucasian groups
Natural History & Prognosis
• Usually benign, but with low malignant potential
• Prognosis: Excellent after surgical resection; usually
curative (95% 5-year survival)
• < 10% metastasize (usually to liver) or recur
Treatment
• Complete surgical excision
DIAGNOSTIC CHECKLIST
Image Interpretation Pearls
• Encapsulated pancreatic tail mass with solid, cystic, and
hemorrhagic components in young non-Caucasian female
SELECTED REFERENCES
1. Ganeshan DM et al: Solid pseudo-papillary tumors of the pancreas: current
update. Abdom Imaging. 38(6):1373-82, 2013
2. Reddy S et al: Surgical management of solid-pseudopapillary neoplasms of
the pancreas (Franz or Hamoudi tumors): a large single-institutional series. J
Am Coll Surg. 208(5):950-7; discussion 957-9, 2009
3. Choi JY et al: Solid pseudopapillary tumor of the pancreas: typical and
atypical manifestations. AJR Am J Roentgenol. 187(2):W178-86, 2006
Diagnoses: Pancreas
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