Features of primary pancreatic lymphoma:A bi-institutional review with an emphasis on typical and atypical imaging features

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 twentynine 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.

Primary pancreatic peripheral T-cell lymphoma:A case report

BACKGROUND Primary pancreatic lymphoma(PPL)is an exceedingly rare tumor with limited mention in scientific literature.The clinical manifestations of PPL are often nonspecific,making it challenging to distinguish this disease from other panc-reatic-related diseases.Chemotherapy remains the primary treatment for these individuals.CASE SUMMARY In this case study,we present the clinical details of a 62-year-old woman who initially presented with vomiting,abdominal pain,and dorsal pain.On further evaluation through positron emission tomography-computed tomography,the patient was considered to have a pancreatic head mass.However,subsequent endoscopic ultrasonography-guided fine needle aspiration(EUS-FNA)revealed that the patient had pancreatic peripheral T-cell lymphoma,not otherwise specified(PTCL-NOS).There was a substantial decrease in the size of the pancreatic mass after the patient underwent a cycle of chemotherapy comprised of brentuximab vedotin,decitabine,and oxaliplatin(brentuximab vedotin and Gemox).The patient had significant improvement in radiological findings at the end of the first cycle.CONCLUSION Primary pancreatic PTCL-NOS is a malignant and heterogeneous lymphoma,in which the clinical manifestations are often nonspecific.It is difficult to diagnose,and the prognosis is poor.Imaging can only be used for auxiliary diagnosis of other diseases.With the help of immunostaining,EUS-FNA could be used to aid in the diagnosis of PPL.After a clear diagnosis,chemotherapy is still the first-line treatment for such patients,and surgical resection is not recommended.A large number of recent studies have shown that the CD30 antibody drug has potential as a therapy for several types of lymphoma.However,identifying new CD30-targeted therapies for different types of lymphoma is urgently needed.In the future,further research on antitumor therapy should be carried out to improve the survival prognosis of such patients.