Clinical approach to pancreatic cystic lesions

Introduction

• Increasingly diagnosed incidentally
• Sequalae of pancreatitis
• Approximately 1-3.5% malignant
• Treatment options range from observation to radical surgery
• Depends on malignant potential
• Highest malignant risk in mucinous cysts
• Pseudocyst is treated if symptomatic or complicated

Types

Benign/Inflammatory Lesions

• Pseudocysts/ WOPN
• Infectious cyst
• Retention cyst
• Lymphoepithelial cyst
• Congenital cyst
• Serous cystadenoma

Cystic Lesions with Malignant Potential

• Intraductal papillary mucinous neoplasm (IPMN)
• Mucinous cystadenoma
• Cystic pancreatic neuroendocrine neoplasms
• Solid pseudopapillary neoplasms
• Cystic malignant tumours (cystic degeneration)
• Cystic ductal adenocarcinoma
• Acinar cancers

History and Presentation

• H/o severe pain abdomen
• H/o Pancreatitis
• Chronic pancreatitis
• Pain abdomen
• Jaundice (yellowing of eyes, skin and urine)
• Feeling of fullness after food or bloating
• Lump in the abdomen
• Incidental

Distinguishing Between Lesions

• History and clinical
• Radiological/ EUS
• Fluid analysis

Work-up

• Ultrasound
• CECT abdomen
• CEMRI
• Endoscopic ultrasound

Radiological Features

• Location
• Ductal relation
• Internal content
• External contour/Wall
• Septal enhancement

High Malignancy Risk Features

• Mural nodules
• Nearby mass
• Thick septa
• Dilated PD

Pathological Features - Cyst Fluid Analysis

• CEA, CA-125, mucin content, cytology, DNA content, detection of genetic mutations
• Cyst fluid glucose
• CEA most reliable - Sensitivity and specificity 73% and 84%
• Cyst fluid mucin content analysis
• MUC1 - pancreatic adenocarcinoma
• MUC 6 - serous cysts
• Cysts with MUC 5A, MUC2 and MUC 1 have the highest risk of being malignant
• Molecular analysis - K-ras mutation and >2 loss of heterozygosity was 96.2% specific for malignancy

Pseudocyst / WOPN

Collection of inflammatory debris lined by a false wall of granulation tissue. May be asymptomatic, symptomatic, infected or complicated (bleed, obstruction [gastric, biliary], rupture).

• Cyst fluid high amylase and lipase
• CT — unilocular hypodense cystic lesions surrounded by smooth dense wall having contrast enhancement
• Radiological evidence of pancreatitis

Management

Observation

• Simple cyst
• Lymphoepithelial cysts
• Small serous cystic neoplasm
• Small branch duct IPMN
• Intraparenchymal spleen

Surgery

Those deemed malignant and at risk of malignancy. Depending on the location and size:

• Whipple
• Distal pancreatectomy
• Spleen preserving
• Central pancreatectomy
• Enucleation

Approach

• Open
• Laparoscopic