SOLID LESIONS OF PANCREASDr Siddaramu K S, 2nd yr M. Ch. ResidentDiscussion: Dr Sanjay Nagral; Consultant GI surgeon, Mumbai
Case history 67 yr/ M Progressive weight loss( 15 kg/ 6 months) Progressive jaundice No Health related problem in the past, No H/o tobacco in any form, nor alcohol. Exercised daily , Vegetarian .
1st seen by Physician -- found to be healthy and Fit Vitals Stable , Systemic exam Unremarkable. Hb - 13.5, TC - 6,500 , ESR - 13 mm at one hour. Blood sugar was 481mg on fasting state. Diagnosed to have MOD, on Gliclazide 160 mg/d. Week later FBS 116mg and PPBS 174 mg .
Continued to lose weight, slower rate. CBC -No change. Diabetes reasonably well controlled , General examination again unremarkable. Thyroid Function- euthyroid status.
US Abdomen Mass 1.9 * 3.1 cms in head of pancreas, Atrophic pancreas and mildly dilated PD. CBD 9 mm dilated , smooth tapering lower end. LFT - TB 4.3 mg- 70% conjugated, SGPT- 75 i.u ALP -841 I.U. CA 19-9 was 14.5 Chest X-ray was normal.
CECT - similar finding to US. Mass located within the pancreas. Fat plane b/t pancreas and stomach maintained. No involvement of major blood vessels. No metastatic disease detected . Clinical diagnosis -- Pancreatic head mass, most probably neoplasm in back ground of chronic pancreatitis.
Hmmmm……… Q: What is your Analysis? What will you do next?
Endoscopic Ultra sonography - carried out . Ill defined mass lesion in the head Pancreas atrophied and slightly hypo- echoic, Mild MPD dilatation ,no stricture or stone . CBD appeared compressed inside the mass but no stone
Mass did not appear to involve major vessels Fat plane between the pancreas and stomach intact.FNA was obtained. Showed inflammatory cells only.
What should I do now? Refer to oncosurgeon? Repeat EUS? Review the FNA sample?
Evaluating Solid lesions ofPancreas Epidemiology Most common presentations Imaging Serology Histology
EUSAdvantages Detect masses as small as 0.2–0.3 cm. Clarify equivocal findings at CT or MR Allows biopsy of suspect lesions. More sensitive than CT (98% vs 86%) Accurate in local tumor staging (67% vs 47%). Pitfalls It is highly operator dependent Presence of SA calcification, Billroth II,large Hiatus hernia, varices Availability Narrow field of view
NET Hypervascular tumor Calcification 20% vs 2% in PDA Vascular infiltration vs Encasement in PDA Less ductal involvement
Solid Pseudopapillary Tumor MC in Tail region Tendency to displace rather than invade surrounding structures Rarely causes obstruction of the bile duct or pancreatic duct. Pseudocapsule has low attenuation at CT Internal hemorragic & cystic degeneration
MRI in solid lesions Fatty infiltration of pancreas & SPT- Inv of Choice Mangafodipir Trisodium enhanced MRI –PDA Better for local extent,vascular involvement than for Lymph node Not Superior to CECT in other lesions.
FDG-PET Preoperatively suspected distant metastasis. Differentiate benign vs malignant Investigate the response to neoadjuvant Rx Currently not a Preop Diagnostic Standard.
Role of ERCP ? Double duct sign in Adenocarcinoma, focal Pancreatitis Biopsy & Brush Cytology- (less sensitive) Pre op Biliary Stenting
SEROLOGY: CA 19-9 Most commonly valued marker (0-37 u/ml) Not specific, high levels seen in benign disease Normalization after resection improved outcome Rising level after resection is a marker of relapse Levels > 1500 correlate with unresectable tumors Not cost effective for screening
Serology Raised Ig G4, ANA Anti smooth muscle, Antihuman lactoferrin Functional Pan NET – Glucagon, Gastrin,VIP…. Pancreatic Lipase – Acinar Cell Ca CEA,CA 242,CA 72-4.-PDA
Histology Difficult to differentiate b/t Ca and CP More stroma and less of cells Small nests, scattered, round ,well delineated units in exocrine back ground (NET) Lymphoplasmacytic infiltration in AIP
Coming back to our patient… IgG-4, grossly elevated Final diagnosis- Autoimmune pancreatitis, with focal inflammatory Mass lesion. Patient was put on 30 mg of prednisolone At 4 wks of Rx, the Mass disappeared.
AIP Classification: Two types1. Type 1 Involves Adults or elderly IdiopathicSecondary to generalized autoimmune process.2. Type 2 Seen in younger children.
AIPJapanese Pancreas Society diagnostic criteria(2002) I. Imaging studies show diffuse narrowing of MPD with irregular wall (>1/3 of length ). II. Lab -abnormally elevated level ( IgG4), or the presence of Auto Antibodies III. Histology shows fibrotic changes with lymphocyte and plasma cell infiltrate. For diagnosis, criterion I must be present with criterion II and/or III .
Take Home Message Accurate diagnosis can be challenging Multimodality imaging approach needed Not all Solid lesions are Malignant Knowledge of relevant clinical information Key radiologic features & Histology Helpful.
References Multimodality Imaging of and Non neoplastic Solid lesionsof the pancreas, Radiographics journal,RSNA,2011. 993-1013 Winter JM, Cameron JL, Lillemoe KD, et al. Periampullary and pancreatic incidentaloma: a single institution’s experience with an increasingly common diagnosis. Ann Surg 2006;243(5):673–680; discussion 680–683. Ros PR, Mortelé KJ. Imaging features of pancreatic neoplasms. JBR-BTR 2001;84(6):239–249. Blumgart’s Surgery of the liver,biliary tract,and Pancreas.