Segaran N, Sandrasegaran K, Devine C, Wang MX, Shah C, Ganeshan D. Features of primary pancreatic lymphoma: A bi-institutional review with an emphasis on typical and atypical imaging features. World J Clin Oncol 2021; 12(9): 823-832 [PMID: 34631445 DOI: 10.5306/wjco.v12.i9.823]
Corresponding Author of This Article
Dhakshinamoorthy Ganeshan, MD, Associate Professor, Department of Diagnostic Imaging, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, United States. dganeshan@mdanderson.org
Research Domain of This Article
Radiology, Nuclear Medicine & Medical Imaging
Article-Type of This Article
Retrospective Study
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Nicole Segaran, Kumaresan Sandrasegaran, Department of Radiology, Mayo Clinic Arizona, Phoenix, AZ 85054, United States
Catherine Devine, Mindy X Wang, Chintan Shah, Dhakshinamoorthy Ganeshan, Department of Diagnostic Imaging, University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States
Author contributions: Segaran N performed data analysis, and wrote the manuscript; Sandrasegaran K, and Ganeshan D designed the research, performed data collection and edited the manuscript; Shah C, and Devine C performed data collection and edited the manuscript; Wang MX contributed to study design and edited the manuscript.
Institutional review board statement: The study was reviewed and approved separately by the Institutional Review Boards of University of Texas MD Anderson Cancer and Mayo Clinic of Arizona.
Informed consent statement: As this is a retrospective review that involves no diagnostic or therapeutic intervention, as well as no direct patient contact, IRB permission was obtained with waiver of informed consent and waiver of authorization to use and review patient information.
Conflict-of-interest statement: The authors declare that they have no conflicts of interest.
Data sharing statement: No additional data is available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Dhakshinamoorthy Ganeshan, MD, Associate Professor, Department of Diagnostic Imaging, University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, United States. dganeshan@mdanderson.org
Received: April 29, 2021 Peer-review started: April 29, 2021 First decision: June 16, 2021 Revised: June 29, 2021 Accepted: August 10, 2021 Article in press: August 10, 2021 Published online: September 24, 2021
Abstract
BACKGROUND
Primary pancreatic lymphoma (PPL) is a rare neoplasm. Being able to distinguish it from other pancreatic malignancies such as pancreatic ductal adenocarcinoma (PDAC) is important for appropriate management. Unlike PDAC, PPL is highly sensitive to chemotherapy and usually does not require surgery. Therefore, being able to identify PPL preoperatively will not only direct physicians towards the correct avenue of treatment, it will also avoid unnecessary surgical intervention.
AIM
To evaluate the typical and atypical multi-phasic computed tomography (CT) imaging features of PPL.
METHODS
A retrospective review was conducted of the clinical, radiological, and pathological records of all subjects with pathologically proven PPL who presented to our institutions between January 2000 and December 2020. Institutional review board approval was obtained for this investigation. The collected data were analyzed for subject demographics, clinical presentation, laboratory values, CT imaging features, and the treatment received. Presence of all CT imaging findings including size, site, morphology and imaging characteristics of PPL such as the presence or absence of nodal, vascular and ductal involvement in these subjects were recorded. Only those subjects who had a pre-treatment multiphasic CT of the abdomen were included in the study.
RESULTS
Twenty-nine cases of PPL were diagnosed between January 2000 and December 2020 (mean age 66 years; 13 males/16 females). All twenty-nine subjects were symptomatic but only 4 of the 29 subjects (14%) had B symptoms. Obstructive jaundice occurred in 24% of subjects. Elevated lactate dehydrogenase was seen in 81% of cases, whereas elevated cancer antigen 19-9 levels were present in only 10% of cases for which levels were recorded. The vast majority (90%) of tumors involved the pancreatic head and uncinate process. Mean tumor size was 7.8 cm (range, 4.0-13.8 cm). PPL presented homogenous hypoenhancement on CT in 72% of cases. Small volume peripancreatic lymphadenopathy was seen in 28% of subjects. Tumors demonstrated encasement of superior mesenteric vessels in 69% of cases but vascular stenosis or occlusion only manifested in 5 out of the twenty-nine individuals (17%). Mild pancreatic duct dilatation was also infrequent and seen in only 17% of cases, whereas common bile duct (CBD) dilation was seen in 41% of subjects. Necrosis occurred in 10% of cases. Size did not impact the prevalence of pancreatic and CBD dilation, necrosis, or mesenteric root infiltration (P = 0.525, P = 0.294, P = 0.543, and P = 0.097, respectively). Pancreatic atrophy was not present in any of the subjects.
CONCLUSION
PPL is an uncommon diagnosis best made preoperatively to avoid unnecessary surgery and ensure adequate treatment. In addition to the typical CT findings of PPL, such as homogeneous hypoenhancement, absence of vascular stenosis and occlusion despite encasement, and peripancreatic lymphadenopathy, this study highlighted many less typical findings, including small volume necrosis and pancreatic and bile duct dilation.
Core Tip: Primary pancreatic lymphoma (PPL) is often misdiagnosed as pancreatic adenocarcinoma. This two-center retrospective study of twenty-nine cases emphasized computed tomography (CT) imaging features useful for distinguishing PPL from its mimics. Distinct CT features of PPL, including a large homogenous hypovascular mass, absence of ductal dilation or atrophy, encasement of mesenteric vessels without invasion, and the presence of small volume peripancreatic adenopathy, should alert the clinicians to the potential diagnosis of this rare neoplasm. This study also demonstrated atypical findings such as necrosis and mild pancreatic or biliary ductal dilation should not rule out the diagnosis of PPL.
