The incidental cystic pancreas mass: a practical approach

Abstract

Technical advances in cross-sectional imaging have led to the discovery of incidental cystic pancreatic lesions in the oncology and non-oncology population that in the past remained undetected. These lesions have created a diagnostic and management dilemma for both clinicians and radiologists: should these lesions be ignored, watched, aspirated, or removed? In this review, recommendations concerning the assessment of the more common pancreatic cystic incidental lesions are presented.

Figure 1

Cystic pancreatic incidentaloma on an MDCT pulmonary embolism study of an 84-year-old man with shortness of breath. Coronal (a) and axial (b) images show an asymptomatic 1.8-cm cystic lesion (arrow) along the anterior aspect of the pancreatic tail. In view of the patient’s age and significant cardiac and pulmonary co-morbidities, it was elected not to follow-up this probably side-branch IPMN.

Figure 2

Cystic pancreatic incidentaloma on an MDCT scan performed to rule out appendicitis in a 45-year-old woman. There is a 1.8-cm cystic lesion with a density of 9 HU in the uncinate process of the pancreas. This probable mucinous cystadenoma has remained stable for 4 years. The patient has declined endoscopic ultrasonography and surgery.

Figure 3

Cystic pancreatic incidentaloma found in a 50-year-old woman on an MR study performed to evaluate abnormal liver function tests. (a) T2-weighted axial MR image shows a 3.2 cm cystic lesion with a mural nodule (arrow) in the pancreatic tail. (b) EUS was performed and demonstrates multiple nodules (arrow) and debris within this mucinous adenocarcinoma. The patient underwent a distal pancreatectomy.

Figure 4

Cystic pancreatic incidentaloma on an MDCT scan performed to evaluate hematuria in a 51-year-old woman. CT shows several septations, areas of minimal mural thickening, and curvilinear calcification within a mass in the pancreatic tail (arrow). A mucinous cystadenocarcinoma was found pathologically.

Figure 5

Cystic pancreatic incidentaloma in a 71-year-old woman who presented with pain in the left lower quadrant. (a) MDCT shows a sponge-like, multiseptated cystic mass in the pancreatic head without biliary or pancreatic ductal obstruction. Despite this classic CT appearance of a serous cystadenoma, the patient and her physician were concerned and endoscopy ultrasonography (b) was performed. This study confirms the innumerable microcystic structures comprising this tumor.

Figure 6

Cystic pancreatic incidentaloma in a 75-year-old woman with hematuria. MDCT depicts a unilocular 2.7 cystic mass (arrow) with a density of 19 HU in the uncinate process of the pancreas. This lesion was aspirated and proved to be an oligocystic serous cystadenoma.

Figure 7

Incidental side-branch IPMNs that can be safely watched. Axial magnetic resonance cholangiopancreatography (MRCP) (a) and coronal MRCP (b) images show a 2.6-cm cystic lesion (arrow) in the pancreatic body that shows no mural thickening or septations. There is no dilation of the pancreatic duct. MRCP images (c,d) from two different patients demonstrate side-branch cystic tumors (arrows) that are not associated with pancreatic duct dilation.

Figure 8

Incidental main-duct IPMNs that need immediate further evaluation. Two axial MDCT images (a,b) show distention of the entire pancreatic duct. There is no pancreatic head mass or biliary dilation. (c) MRCP image in a different patient shows a nodule in the main pancreatic duct as well as multiple side-branch IPMNs.

Figure 9

Flowchart for imaging workup of incidental pancreatic masses in asymptomatic patients. As with all guidelines, these are not meant to be a rigid set of rules, but rather a starting point for clinically relevant decision making. BD-IPMN, branch-duct intraductal papillary mucinous neoplasm; US, ultrasonography. (1) Signs and symptoms include hyperamylasemia, recent onset diabetes, severe epigastric pain, weight loss, steatorrhea, or jaundice. (2) Consider decreasing interval if younger, omitting with limited life expectancy. Recommend limited T2-weighted MRI for routine follow-ups. (3) Recommend pancreas-dedicated MRI with MRCP. (4) If no growth after 2 years, follow yearly. If growth or suspicious features develop, consider resection.