Pancreatic colloid adenocarcinoma arising from intraductal papillary mucinous neoplasm: Radiologic-pathologic correlation with cinematic rendering

Abstract

Intraductal papillary mucinous neoplasms (IPMN) of the pancreas have the potential for malignant progression into adenocarcinoma. Colloid or mucinous non-cystic carcinoma of the pancreas is an uncommon variant neoplasm that can arise within an intestinal type IPMN and have a relatively improved prognosis but may mimic the more lethal tubular or ductal adenocarcinoma. Colloid carcinoma is an infiltrating ductal epithelial neoplasm containing primarily extracellular stromal mucin pools and scant amount of centrally floating neoplastic cells. While several reports have evaluated the unique pathologic and immunohistochemical profile of colloid carcinomas, there has been limited radiologic-pathologic correlation in the literature. We report a case of an 83-year-old female who presented for evaluation of slowly progressive abdominal pain and was found to have colloid carcinoma arising from an IPMN. This is one of the first reports to correlate the multimodality radiology including cinematic rendering (CR) and histopathology features associated with this tumor. An enhanced understanding of the correlation between imaging appearance and specific histopathologic findings may aid in the early recognition and treatment of this rare neoplasm. Emphasis is placed on CR as this may help guide surgical management.

Keywords: cinematic rendering; colloid adenocarcinoma; intraductal papillary mucinous neoplasm.

Figure 1.

(a) Noncontrast axial CT image through the pancreas demonstrates a hypodense mass expanding the pancreatic body and tail. Associated main pancreatic duct dilatation is noted. (b) Arterial phase post contrast CT demonstrates peripheral solid enhancing components within the pancreatic mass. No vascular invasion or distant metastases were noted. (c) Axial fused PET/CT shows hypermetabolic activity within the solid peripheral enhancing components of the pancreatic mass. SUV max of the solid components was 5.2. CT: Computed tomography; PET: Positron emission tomography.

Figure 2.

(a) Axial T2 weighted MR shows marked pancreatic ductal dilatation with a complex cystic mass with multiple poorly defined lower T2 signal filling defects. (b) Axial T1 weighted fat saturated non-contrast and (c) arterial phase post contrast show central low T1 signal with peripheral increased T1 corresponding to the solid peripheral components. (d) Coronal T2 weighted MR demonstrates the expanded nature of the pancreatic tail secondary to a high T2 signal mucinous lesion. (e) Axial DWI b value 1000 and (f) Axial ADC map demonstrate multi focal restricted diffusion within the pancreatic tail and body lesion. MR: Magnetic resonance; DWI: Diffusion weighted imaging; ADC: Apparent diffusion coefficient.

Figure 3.

(a) and (b) Endoscopic ultrasound images of the large pancreatic mass involving the body and tail. The complex cystic nature is appreciated with the overall hypoechoic appearance of the mass with multiple scattered hyperechoic foci corresponding to the mucinous nature of colloid adenocarcinoma.

Figure 4.

(a) Axial CT image (cinematic rendering) through the pancreatic tail mass. (Syngo Via, Siemens Healthcare, Erlangen, Germany) (b) Corresponding axial post contrast venous phase image through the pancreatic mass. (c) Coronal oblique cinematic rendered image through the pancreatic tail mass. Note the visualization of vasculature surrounding the pancreatic lesion. (d) Corresponding post contrast coronal reconstructed CT image. CT: Computed tomography.

Figure 5.

Mucinous (colloid) adenocarcinoma arising in an IPMN. (a) and (b) Low and high magnification of IPMN with pancreatic parenchyma alteration and high-grade morphology (arrows). (c) and (d) Colloid carcinoma and mucin dissecting fibrotic stroma, with detachment (arrow). (e) Colloid carcinoma abuts an artery (arrow); benign glands do not share this behavior. (f) Colloid carcinoma and mucin surrounds and abuts a nerve bundle (arrow). IPMN: Intraductal papillary mucinous neoplasms.