Podoplanin & its role in diagnosis of cancer invasion
1. PODOPLANIN IN TUMOR INVASIONPODOPLANIN IN TUMOR INVASION
– A PROMISING NEW APPROACH– A PROMISING NEW APPROACH
DR RATNADEEP GANGULY
MD, DNB, MIAC, MNAMS
Consultant Surgical Pathologist
DR TIBAR BANNERJEE
MS, MCh
Consultant Plastic Surgeon
THE MISSION HOSPITAL
Durgapur, INDIA
8. DIAGNOSTIC PITFALLS WITH ONLY
HISTOMORPHOLOGICAL EXAMINATION
Well oriented sections as opposed tangential sections
Inflammation, edema & fibrosis around invasive nests
Certain parameters subjective
Detached nests of benign mucosa
Dysplastic mucosa in head/neck may be a little
thickened appearing like a mass
Squamous mucosa forming in salivary acini
9. PATTERNS OF TISSUE INVASION
SINGLE CELL INVASION
Mimics early developmental process
(epithelial-mesenchymal transition)
Loss of E-cadherin expression
COLLECTIVE CELL MIGRATION
Less well understood
Podoplanin expression
Upregulated at the edges of large
tumor masses eg. SCC of lip, oral
cavity, ovarian granulosa cell tumor,
mesothelioma
10. SINGLE CELL INVASION LOSS OF
E-cadherin(BROWN) NO
PODOPLANIN
COLLECTIVE CELL MIGRN
NO
LOSS OF E-cadherin
PODOPLANIN(RED) AT
ADVANCING EDGE
11. WHAT IS PODOPLANIN ?
Protein expressed in most human tissues
Upregulated in tumor edges
Bypasses epithelial-mesenchymal transformation in
carcinogenesis
Promotes tumor cell spreading, migration &
invasion
12. WHAT IS PODOPLANIN ? – contd.
SCC, CNS tumors & germinal neoplasms are +ve
Collective cell migration - +ve
Invasion of single cells / small cell groups
(Adenocarcinomas) - –ve
Good adjunct in detection of equivocal invasion /
microinvasion in SCC of skin, lip, oral cavity
13. OTHER MEANS TO DETECT TUMOR INVASION
DEMONSTRATION OF BASEMENT MEMBRANE / BASAL
CELL LAYER BY:
Cytochemistry:
Methenamine silver stain (black reticulin fibers)
PAS reaction (magenta)
Immunohistochemistry:
Collagen type IV & VII
Laminin
High mol wt cytokeratin (HMWCK - 34Eβ12) – Basal layer
Basement membrane
Basement
membrane