Synonyms: Pancreatic serous cystic neoplasm, microcystic adenoma of pancreas

Commonly in body and tail; 30% in pancreatic head

Variable size; mean: 4.9 cm

Well-demarcated, lobulated, heterogeneous mass with posterior acoustic enhancement

Microcystic type: “Honeycomb” cystic mass with septa and solid-appearing component

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  Cluster of > 6 cysts; each typically < 1 cm

  
  
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  Central echogenic scar (30%); ± calcification

  
  
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  Solid, echogenic appearance due to interfaces between microcysts

Macrocystic type: Unilocular or fewer larger cysts (> 2 cm)

CT: Better characterization of classic honeycomb pattern

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  Cluster of > 6 cysts; each typically < 1-2 cm

  
  
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  Coalescing enhancing septa → central scar ± calcification

  
  
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  May mimic solid mass

MR: Can better identify T2-hyperintense cysts separated by T2-hypointense septa

Endoscopic ultrasound: May allow for presumptive diagnosis based on typical features

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  Higher spatial resolution than transabdominal ultrasound → often diagnostic for microcystic form

  
  
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  Can be used to guide fine-needle aspiration of cyst fluid for indeterminate cases e.g., macrocystic variant

Pancreatic and common bile duct dilatation not typical

Increased vascularity within septa

Pancreatic pseudocyst

Mucinous cystadenoma of pancreas

Intraductal papillary mucinous neoplasm

Cystic neuroendocrine tumor

Ductal pancreatic carcinoma

Solid pseudopapillary neoplasm

Cysts lined by small cuboidal epithelial cells with clear cytoplasm and minimal mucin

Subtypes: Microcystic and oligocystic/macrocystic

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  WHO classification

  
  
  
  
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    Serous microcystic adenoma: Sponge-like/honeycomb or polycystic mass with central scar

    
    
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    Serous oligocystic adenoma/macrocystic variant: Unilocular or with few large cysts (less common)

  
  

Benign epithelial neoplasm arising from centroacinar cells of exocrine pancreas and composed of small cysts containing proteinaceous fluid separated by fibrovascular connective tissue septa

May be multiple in von Hippel-Lindau disease

20% of all cystic pancreatic lesions; 1% of pancreatic neoplasms

Middle and elderly age group; mean: 61.5 years, M:F = 1:4

Typically asymptomatic or vague epigastric pain; may present with nausea, vomiting, weight loss, palpable mass, jaundice

Typically benign and slow growing

Nearly no malignant potential

Very rare tumors may behave aggressively or become symptomatic (large lesions or lesions in head)

Asymptomatic and small tumors: Imaging surveillance at 6- to 12-month intervals until stability demonstrated over 2-year period

Symptomatic and large tumors → complete surgical excision

Depending on body habitus, consider higher frequency transducers to depict characteristic cluster of small cysts within mass