pancreas

1. RECENT ADVANCES IN
PANCREATIC PATHOLOGY
Presented by: Surgeon Lt Cdr N Dogra
GUIDE: COL R B BATRA

2. • Classification
• Precursor lesions
• Pancreatic endocrine neoplasms
• Familial endocrine neoplasms
• Pancreatic cytopathology
• CAP protocols
• Advances in acute pancreatitis pathogenesis
• Pancreatic transplant

3. INTRODUCTION
• Pancreatic cancer - fourth leading cause of
death among both men and women, comprising
6% of all cancer-related deaths.
• At the time of diagnosis - 52% of all patients
have distant disease & 26% have regional
spread.
• The relative 1year survival - only 24%, and the
overall 5-year survival rate for this disease is
less than 5%.
• Incidence in India - less than 2 cases per
100,000 persons per year.
(Pancreatic Cancer: eMedicine Oncology Pancreatic Cancer
Author: Richard A Erickson, MD, FACP, FACG, Professor of Medicine, Division of Gastroenterology, Department of Internal Medicine,
Texas A&M University Health Science Center; Director, Scott and White Clinic and Hospital Updated: Apr 7, 2009)

4. The pancreatic lesions can be divided into
Endocrine Exocrine
Diabetes Neoplasms Acute & Neoplasms
Mellitus chronic
pancreatitis

5. CLASSIFICATION

6. WHO CLASSIFICATION OF EXOCRINE OF TUMOURS OF
PANCREAS
(Pathology and genetics, Tumours of digestive system IARC WHO CLASSIFICATION no. 2,
Hamilton, S. R , Aaltonen, L.A)
• Epithelial tumors
Benign
Serous cystadenoma
Mucinous cystadenoma
Intraductal papillary mucinous adenoma
Mature teratoma
Borderline (uncertain malignant potential)
Mucinous cystic neoplasm with moderate dysplasia
Intraductal papillary mucinous neoplasm with
moderate dysplasia
Solid pseudopapillary neoplasm

7. • Malignant
Ductal adenocarcinoma
Mucinous noncystic carcinoma
Signet-ring-cell carcinoma
Adenosquamous carcinoma
Undifferentiated (anaplastic) carcinoma
Undifferentiated carcinoma with osteoclastlike
giant cells
Mixed ductal-endocrine carcinoma
Serous cystadenocarcinoma
Mucinous cystadenocarcinoma
Noninvasive
Invasive

8. Malignant tumors (cont)
• Intraductal papillary mucinous carcinoma
Noninvasive
Invasive (papillary mucinous carcinoma)
Acinar cell carcinoma
Acinar cell cystadenocarcinoma
Mixed acinar-endocrine carcinoma
Pancreatoblastoma
Solid pseudopapillary carcinoma
Other
Nonepithelial tumors
Secondary tumors

11. PANCREATIC PRECURSOR
LESIONS

12. • Invasive pancreatic cancer develops through
stepwise tumor progression
• Based on pathologic, clinical, and genetic
observations.
• The progression of normal pancreatic epithelium
to infiltrating cancer - through a series of
histologically defined lesions called as PanINs

14. Pancreatic Intraepithelial Neoplasias (PanIN)
and Corresponding Older Synonyms
Squamous metaplasia: Epidermoid metaplasia, multilayered metaplasia
PanIN-1A: Pyloric gland metaplasia, goblet cell metaplasia, mucinous hypertrophy, mucinous ductal
hyperplasia, mucinous cell hyperplasia, mucoid transformation, simple hyperplasia, flat duct lesion without
atypia, flat ductal hyperplasia, ductal hyperplasia grade 1, nonpapillary epithelial hypertrophy, nonpapillary
ductal hyperplasia
PanIN-1B: Papillary hyperplasia, papillary ductal hyperplasia, papillary ductal lesion without atypia, ductal
hyperplasia grade 2, adenomatous ductal hyperplasia, adenomatoid hyperplasia
PanIN-2: Atypical hyperplasia, papillary duct lesion with atypia, low-grade dysplasia, any PanIN lesions with
moderate dysplasia
PanIN-3: Carcinoma in situ, intraductal carcinoma, severe ductal dysplasia, high-grade dysplasia, ductal
hyperplasia grade 3, atypical hyperplasia

15. • Molecular genetic alterations are well known
now
• Cumulative genetic disarrays -potential markers
for early diagnosis & target for intervention
• Genetic alterations in (PanIN-1 and 2)
- telomere shortening,
-activating mutation in codon 12 of KRAS
-inactivation of CDKN2A/p16 tumour
suppressor gene.

16. • PanIN-3
-additional molecular alterations
-inactivation of tumor suppressor gene
SMAD4/DPC4, TP53, and BRCA2.

18. • Increased expression of proteins in ductal
pancreatic acini in PanIN lesions
• Cyclin D1 overexpression is associated with
poor prognosis
• Not seen in normal pancreatic ducts or PanIN 1
• Cyclooxygenase 2 –a rate limiting enzyme in PG
pathway – over expression is implicated in
tumour cell growth, invasion, angiogenesis, and
prognosis

19. • Cyclooxygenase 2 overexpression -potential
target for chemotherapy by selective COX-2
inhibitors.
•
• Other preinvasive lesions
-intraductal papillary mucinous neoplasms
-mucinous cystic neoplasms

20. • IHC labeling of genes
-CDKNIA, MMP7, CLDN18, ANXA2,
S100P
-progressive increase in their expression
from low to high grade PanINs.
• Gene products
-are proposed to be good candidates
-validated in serum and urine as early
markers of pancreatic cancer.

23. PANCREATIC ENDOCRINE
NEOPLASMS

24. • Morphology allows distinction between poorly
differentiated and well differentiated neoplasms.
• Well differentiated constitute >90 % of PEN
- poorly differentiated are invariably high grade
malignancies
• Well differentiated endocrine carcinomas -
morphologically similar to well differentiated
endocrine tumors.

27. • The WHO has differentiated endocrine
tumors from endocrine carcinomas
• Prognostic stratification of well differentiated
endocrine carcinomas - not done in WHO
classification
• European Neuroendocrine Tumor Society
- proposed a TNM based staging system
for gastroenteropancreatic endocrine tumors

30. Immunohistochemistry
• General endocrine markers-
- labeling with atleast one of the general
endocrine markers - synaptopyhsin,
chromogranin.
- poorly differentiated endocrine tumors -
usually negative for Cg A but retain their
synaptophysin labeling
- circulating CgA can also be used as a tumor
marker for PENs

32. • Ki67 (MIB-1 antibody)
-proliferative activity is an integral part of the
WHO classification
-assessment should be made in the ‘hot
spot’
-at least 40 HPF (1 HPF=0.2 mm2) should be
screened or 2000 tumor cells counted
-Use of grid or printed microscopic picture of
selected field

33. • Hormones
- Confirmation of resected PET as a source
of the clinically observed hormone
hypersecretion
- Identification of functioning PETs
- Confirmation of neoplastic nature of
small PETs

34. • Additional markers
–Cytokeratin 8 and 18 are constantly
positive, 7 & 20 are usually negative
- Cytokeratin 19 is regarded as a marker for
aggressiveness
–Trypsin - marker for acinar differentiation
–if >25 % of neoplastic cells are positive
(mixed acinar-endocrine carcinoma)
–COX2, P27, CD99

35. Genetic studies in PENs
• MEN type 1:
- pancreatic microadenomatosis
-seen in more than 80 % of MEN-1,are now
considered to be precursor lesion of PENs.
• Loss of heterozygosity
-mono hormonal islet like endocrine cell
clusters found in MEN 1 pancreas
-identified as fore runners of microadenomas

36. • Hereditory syndromes like VHL, Tuberous
sclerosis - No precursor lesion identified

37. • Chromosomal anomalies –associated with
tumor burden and stage of the disease
.
• DNA copy number status - proposed as the
most sensitive and efficient marker of clinical
outcome of insulinomas.
• Chromosomal instability - associated with
tumor progression.

38. • Chromosomal losses -more frequent than gains
& amplifications
• Most common gains – chromosomes 5q, 7pq,
9q, 14q, 20q
• Most common losses - 1p, 3p, 11q, 6q
• Epigenetic anomalies - occur but there role in
tumorigenesis not yet proved

39. Gene expression alterations
• Protein coding RNAs – assessment of the
expression levels of particular genes
• Regulatory micro RNAs - particular pattern of
micro RNA expression distinguishes PEN from
normal pancreas and acinar carcinoma
• miRNA-204 is primarily expressed in
insulinomas
• miRNA -21 is - high proliferation index and
metastasis to liver

40. FAMILIAL PANCREATIC CANCER

41. • 5 % to 10 % of individuals with pancreatic
cancer - history in close family member
• Several known genetic syndromes - increased
risk of pancreatic cancer
• Known genes explain - only a portion of the
clustering of pancreatic cancers
• Research has been on to identify additional
susceptibility genes

43. • Surgically resected pancreas with strong family
history - multifocal PanINS with lobulocentric
atrophy.
• Appear as heterogenous mass on EUS and CT
• At risk individuals can be screened - early
curable neoplasms detected before they
progress to invasive cancer.

45. Screening at risk patients for early
pancreatic neoplasia
• Combination of computed tomography, EUS,
ERCP
• FAMILIAL CASES-harbour more multifocal
precursor lesions, can be confirmed using KRAS
gene mutation analysis
• Lobulocentric atrophy- common finding in
familial cases.

46. PANCREATIC CYTOPATHOLOGY

47. • Pancreatic cytology has become very important
due to advanced imaging technology and ESU
• The combination of cytology and radiology
• Under the multimodal approach to pancreatic
tumor diagnosis-cytology is presently combined
to radiological techniques

48. • CT,USG, MRI, Magnetic resonance
cholangiopancreaticography, ERCP (esp.for
obstructive jaundice and bile duct stricture) with
biliary brushings.
• EUS (Endoscopic ultrasound guided)-FNA-( esp
for patients with small mass lesions in the body
and tail and pts with cystic lesions).
• Lymph node staging and the detection of
metastatic lesions are essential aspects of
pancreatic cancer staging.
.

49. • EUS-FNA allows for sampling of suspicious-
appearing peripancreatic lymph nodes and liver
lesions
• Increases the accuracy of lymph node staging
and can preoperatively stage pancreatic cancer
• Percutaneous aspirates under CT or USG-can
be used if above are unavailable
• Brushings and intraductal aspirates procured by
ERCP can be processed via monolayer
technology

53. Well differentiated ductal
adenocarcinoma
Undifferentiated pancreatic
carcinoma

58. • Development of newer molecular markers –
identification of cancer at an early stage.
• Common genetic alterations - activating point
mutations in codon 12 of KRAS, silencing of
p16, TP53 and DPC4
• Similar changes in KRAS2
-utilised for diagnostic purposes
-parallels the sensitivity of cytologic analysis
.

59. • Other potential markers
- aberrantly expressed proteins and mucins
identified through mRNA expression profiling
• Specific markers
-prostrate stem cell antigen, mesothelin, and
MUCI
• Barriers - reliance on presence of substantial
diagnostic material
- imperfect specificity
-cost

60. CAP PROTOCOLS

61. EXOCRINE NEOPLASMS

73. T4

74. Regional lymphnodes

75. Regional L.N (contd.)

81. ENDOCRINE NEOPLASMS OF
PANCREAS

86. • Tumor dimensions – endocrine
microadenomas (< 5 mm)
• Tumor multifocality
– seen in majority of MEN 1 cases
- careful gross examination of resected
specimen with systemic sectioning at 3-5 mm

87. • Ancillary techniques

88. ACUTE PANCREATITIS

90. • Initiating cellular events - acinar cell injury
• Co-localization of zymogens with lysosomal
hydrolases,
• Premature enzyme activation
• Pathological exocytosis of zymogens into the
interstitial space.
• Accentuation of cell injury
• Triggering of acute inflammatory mediators

91. • Intensification of oxidative stress
• Compromise of microcirculation
• Activation of a neurogenic feedback
• Localized events progress to a systemic
inflammatory response
• Multiorgan dysfunction syndrome

92. PREMATURE ACTIVATION OF PANCREATIC
ENZYMES WITHIN THE PANCREATIC ACINAR CELL
• Hyperstimulation model – cholecystokinin
• Missorting & co-localization of zymogens with
lysosomal cathepsin B within large cytoplasmic
vacuoles
• Trypsinogen cleavage and activation

93. BASOLATERAL EXOCYTOSIS INTO THE
INTERSTITIAL SPACE
Misdirection to the basolateral plasma
membrane
Shown recently by real-time imaging of single
ZG exocytosis in supra-maximal CCK-stimulated
rat pancreatic acinar cells
Molecules mediating basolateral exocytosis
have been elucidated

94. (SNAP) receptor (SNARE) hypothesis
Cytosolic N-ethylmaleimide-sensitive factors &
soluble SNAPs bind SNAREs on donor vesicles
& target membranes
Multimolecular complexes formation
The union between v- and t-SNAREs
Fusion of the two membranes

95. • There is specificity of membrane fusion events
• Compartmental specificity of distinct sets of v-
SNARE and t-SNARE proteins
• Accessory proteins regulate the SNARE
complex assembly

96. ROLE OF INFLAMMATORY MEDIATORS
Acini undergoing injury release zymogens,
particularly trypsin
Induce macrophages to synthesize and release
proinflammatory cytokines
Neutrophil recruitment and activation within the
pancreatic tissue
Acinar cells themselves can synthesize cytokines,
which amplify the local inflammatory response

97. • TNF-α has direct actions on acini - activation
and disruption of the actin cytoskeleton
• TNF-α can also induce apoptosis
NF-κB is a transcription factor that promotes the
expression of proinflammatory cytokines
Supramaximal CCK stimulation in vitro or in vivo,
causes NF-κβ activation within acinar cells

98. NEUROGENIC INFLAMMATION
Stimulation of primary sensory neurons trigger
autonomous arc reflexes (AARs)
• Acute, neurogenic inflammatory response
initiated in the pancreatic tissue
• AARs integrate the duodenum autonomic nerve
fibres with those from the celiac ganglion and
bulbar-hypothalamic nuclei
• Sensory neurons in the pancreas contain
unmyelinated, capsaicin-sensitive (type C) nerve
fibres release sensory peptides

99. Substance P, neurokinin A and vasoactive
intestinal peptides
Peptides act on mast cells, causing release of
histamine and proinflammatory mediators

100. • New imaging modalities have enhanced the
understanding and management of acute
pancreatitis
• Radiographic assessment of the extent of
inflammation and necrosis within 48 hours
• It allows for a more standardized diagnosis,
severity assessment, treatment plan, and
complication identification

101. PANCREATIC TRANSPLANTATION

102. • Increasingly accepted as a treatment for young
to middle-aged adults afflicted with insulin-
dependent diabetes mellitus (type 1)
• Allograft rejection can be assessed by needle
biopsies of the graft and/or cytologic studies of
pancreatic juice drained from the graft

103. • Forms of rejection, including the grade of
severity (0 to V), need to be separated from
nonimmunologic causes of allograft dysfunction

104. 2007 Banff Schema for Grading of
Acute Pancreas Allograft Rejection

105. Category Histopathology Comments
Normal No inflammation OR inactive
septal mononuclear
inflammation not involving
veins, arteries, ducts, or acini
Fibrous tissue limited to
septa in appropriate
amounts; no injury or
atrophy of acinar regions
Indeterminate for Acute Rejection
Active" septal inflammation
without other criteria for
rejection (see below)
1. Any venulitis or ductitis
qualifies for at least mild
acute rejection (or more
depending on other features)
2. Active inflammation refers
to blastic lymphoctyes with
variable numbers of
eosinophils
Grade I (Mild acute cell-
mediated rejection
Active" septal inflammation
with involvement of septal
veins (venulitis) and/or ducts
(ductitis)
AND/OR focal (1-2
foci/lobule) acinar "active"
inflammation with
minimal/no acinar cell injury
1. Any venulitis or ductitis is
sufficient for diagnosis; nerve
branches usually involved but
rarely sampled; focal acinar
"active" inflammation alone
also adequate for diagnosis

106. Grade II (Moderate acute cell-
mediated rejection)
Minimal intimal arteritis
AND/OR multiple (3 or more
foci/lobule) foci of acinar
"active" inflammation with
single cell injury/dropout
1. Any venulitis or ductitis is
sufficient for diagnosis; nerve
branches usually involved but
rarely sampled; focal acinar
"active" inflammation alone
also adequate for diagnosis
Grade III (Severe acute cell-
mediated rejection)
Widespread acinar
inflammation with confluent
areas of acinar cell
injury/necrosis
AND/OR moderate to severe
intimal arteritis
AND/OR necrotizing arteritis
Any of these three findings is
sufficient for the diagnosis
1. Acinar inflammation may
contain variable lymphocytes,
eosinophils, and neutrophils
as well as edema and/or
hemorrhage
2. Moderate/severe intimal
arteritis consists of more
frequent subendothelial
lymphocytes with evidence of
intimal injury, such as cell
swelling, fibrin leakage, etc.
3. Necrotizing arteritis may
also occur in antibody-
mediated rejection and C4d
stain should be performed.

107. Chronic Active Cell-Mediated
Rejection
Chronic active cell-
mediated rejection
Arterial luminal
narrowing due to intimal
proliferation of
fibroblasts,
myofibroblasts, smooth
muscle cells, with
admixed T lymphocytes
and macrophages
("active" transplant
arteriopathy)
1. May represent
transition between
intimal arteritis and
chronic transplant
arteriopathy related to
suboptimal
immunosuppression
2. Rarely seen in needle
biopsies, more often
seen in allograft
resection related to
chronic rejection

108. Antibody-Mediated Rejection
Category Histopathology Comments
Hyperacute antibody-mediated
rejection
Widespread deposition of
immunoglobulin (usu. IgG) and
complement (e.g., C4d) with
resultant arteritis and venous
thrombosis, hemorrhagic necrosis
and allograft failure usually within 1
hour after revascularization
1. In all cases, diagnosis is
dependent upon demonstration of a)
graft dysfunction, b) capillary
complement deposition (i.e., C4d
positivity), AND c) donor specific
antibodies in serum.
2. If C4d and only 1 of the other 2
features is found, then the
diagnosis"suspicious for" antibody-
mediated rejection is more
appropriate
3. In cases in which vascular
thrombosis is the predominant
finding, the differential diagnosis lies
between antibody-mediated
rejection and "technical failure“.
Accelerated antibody-mediated
rejection
Similar to hyperacute, but changes
evolve over hours to days after
revascularization.
Acute antibody-mediated rejection Allograft dysfunction in first
posttransplant weeks; histology
varies from normal to margination of
neutrophils and mononuclear cells
to thrombosis and necrosis;

109. REFERENCES
• Rosai J, Rosai and Ackerman’s Surgical Pathology , ninth
edition, Elsevier
• Kumar, Abbas, Fausto , Robbins and Cotran Pathologic
Basis Of Disease, eighth edition, Elsevier
• Stephen S. Sternberg, Stacey E. Mills, Darryl Carter,
Sternberg's Diagnostic Surgical Pathology, fifth edition,
2009
• Caroline S Verbeke, Review-Endocrine tumours of the
pancreas; Histopathology 2010, 56, 669-682
• Ralph H, Hruban, MD, Giuseppe Zamboni et al, Special
issue-Insights and Controversies in Pancreatic Pathology;
Arch Pathol Lab Med, March 2009, vol 133: 147-399

110. • Kay Washington, Jordan Berlin et al , Protocol for the
Examination of Specimens from Patients with Carcinoma of
the Endocrine Pancreas and Exocrine Pancreas; AJCC/UICC
TNM, 7th edition (Protocol web posting date: October 2009)
• LI Cosen-Binker, HY Gaisano. Recent insights into the cellular
mechanisms of acute pancreatitis. Can J Gastroenterol 2007;
21(1):19-24.
• Drachenberg CB et al, Banff schema for grading pancreas
allograft rejection:working proposal by a multi-disciplinary
international consensus panel, Am J Transplant 2008; 8 :1-13