Diagnostic Ultrasound - Abdomen and Pelvis

Cystic Pancreatic Lesion
Helpful Clues for Less Common Diagnoses
• Necrotic Pancreatic Ductal Carcinoma
○ Most common pancreatic neoplasm
○ Malignant lesion
○ Commonly in head of pancreas
○ Typically appears as an ill-defined, solid, hypoechoic mass
with ductal obstruction
○ May show complex cystic areas due to tumor necrosis,
side branch obstruction or adjacent pseudocyst
– Uncommon form of common neoplasm
○ Infiltrative appearance ± vascular invasion distinguishes
this entity from other solid malignancies that may show
cystic change
○ Obstructive symptomatology
• Solid Pseudopapillary Neoplasm
○ Tumor with low-grade malignant potential
○ Commonly in the pancreatic tail
○ Well-defined, large heterogeneous echogenic solid and
cystic mass
○ Cystic areas are secondary to tumor degeneration and
vary in size and morphology
○ Prominent vascular soft tissue components
○ Often shows intratumoral hemorrhage
○ Typically seen in young women (< 35 years)
• Cystic Pancreatic Neuroendocrine Tumor
○ All tumors > 5 mm considered malignant
○ Typically round, solid, hypoechoic mass with internal
color Doppler flow
○ Central cyst formation may occur due to tumor
degeneration
– Uncommon form of uncommon neoplasm
○ Identification of hypervascular rim can be challenging
○ Familial syndromes: Multiple endocrine neoplasia type I;
von Hippel-Lindau; neurofibromatosis type I; tuberous
sclerosis
– May have multiple lesions
– Occurs in younger patients (< 40 years)
• Congenital Cyst
○ True epithelial lining with serous fluid
○ Consider in patients with autosomal dominant polycystic
kidney disease, von Hippel-Lindau and cystic fibrosis
– Usually multiple; can replace entire pancreas (e.g., in
cystic fibrosis)
• Lymphoepithelial Cyst
○ Rare, benign, lesion usually in tail of pancreas
○ Nonneoplastic, no malignant behavior
○ Macrocystic morphology, multilocular or unilocular cysts
○ May see characteristic T1 hyperintensity and low T2
signal due to keratin content
○ Almost exclusively in middle-aged to elderly men
• Cystic Metastases
○ Pancreatic metastases are uncommon
○ Can occur with renal cell carcinoma, melanoma, breast
cancer, lung cancer, gastric cancer, colorectal carcinoma
SELECTED REFERENCES
1. Kim YS et al: Rare nonneoplastic cysts of pancreas. Clin Endosc. 48(1):31-8,
2015
2. Goh BK et al: Are the Sendai and Fukuoka consensus guidelines for cystic
mucinous neoplasms of the pancreas useful in the initial triage of all
suspected pancreatic cystic neoplasms? A single-institution experience with
317 surgically-treated patients. Ann Surg Oncol. 21(6):1919-26, 2014
3. Sahani DV et al: Diagnosis and management of cystic pancreatic lesions. AJR
Am J Roentgenol. 200(2):343-54, 2013
4. Megibow AJ et al: The incidental pancreatic cyst. Radiol Clin North Am.
49(2):349-59, 2011
5. Hutchins G et al: Diagnostic evaluation of pancreatic cystic malignancies.
Surg Clin North Am. 90(2):399-410, 2010
6. Kalb B et al: MR imaging of cystic lesions of the pancreas. Radiographics.
29(6):1749-65, 2009
Differential Diagnoses: Pancreas
Pancreatic Pseudocyst
Pancreatic Pseudocyst
(Left) Transverse
transabdominal ultrasound
shows a well-demarcated,
anechoic lesion with
through transmission ſt in the
tail of the pancreas,
compatible with a pseudocyst.
(Right) Axial CECT in the same
patient demonstrates a welldemarcated,
low-density cystic
lesion with a thin wall in
the tail of the pancreas. Note
the lack of enhancing
components and marked
pancreatic atrophy.
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