tumor markers and cyst fluids

Question 1

Serum AFP is elevated in a young woman

Answer 1

*FIRST think yolk sac tumor
An elevated AFP level in a young woman most frequently suggests a yolk sac tumor or yolk cell components in a mixed germ cell tumor.
*PITFALLS –> AFP elevations have been reported in Sertoli-Leydig cell tumors without yolk sac elements.

Question 2

Chemistries for pancreatic pseudocyst

Answer 2

elevated amylase
decreased CEA
elevated CA19-9

Question 3

Chemistries for serous cystadenoma

Answer 3

decreased amylase
decreased CEA
decreased CA19-9
*down for the count
*central stellate scar, honeycomb appearance, PAS positive glycogen, inhibin, glut-1, MUC6

Question 4

Chemistries for solid pseudopapillary tumor

Answer 4

decreased amylase
decreased CEA
decreased CA19-9
*down for the count (same as serous cystadenoma)

Question 5

Chemistries for mucinous cystic neoplasm

Answer 5

decreased amylase (not connected to ducts)
INCREASED CEA (mucinous)
normal or near normal CA19-9

Question 6

Chemistries for intraductal papillary mucinous neoplasm

Answer 6

INCREASED amylase (ductal connection)
INCREASED CEA (mucinous)
normal or near normal CA19-9

Question 7

5 separate fluid-filled entities to consider in a pancreas

Answer 7

(3 non-mucinous)
pseudocyst
serous cystadenoma
solid pseudopapillary tumor
(2 mucinous)
intraductal papillary mucinous neoplasm
mucinous cystic neoplasm

Question 8

Serous cystadenoma IHC profile

Answer 8

IHC: Positive for inhibin, Cytokeratin, GLUT-1, and MUC6
*think von Hippel Lindau Syndrome (VHL)
*benign, but rarely can transform to carcinoma
*more commonly female

Question 9

High yield AP info for mucinous cystic neoplasm of pancreas

Answer 9

Gross: Multilocular cyst surrounded by a thick fibrotic capsule
Microscopy: Cyst-forming, mucin-producing neoplasm with a distinct ovarian-type subepithelial stroma in the wall
*NEED OVARIAN TYPE STROMA
IHC: Ovarian stroma stains- ER, PR, Inhibin, and Smooth muscle actin; Lining epithelium stains- cytokeratin, CEA and MUC5AC
*exclusively in females, body or tail of pancres
*SAMPLE extensively, because of possible invasive component driving prognosis
*KRAS mutations common
*TP53 and SMAD4 mutations possible

Question 10

TP53 and SMAD4 mutations in a pancreas cyst

Answer 10

mucinous cystic neoplasm

Question 11

KRAS mutations in a pancreas cyst

Answer 11

mucinous cystic neoplasm

Question 12

Ovarian type stroma in a pancreas lesion

Answer 12

mucinous cystic neoplasm
*be concerned about von hippel lindau syndrome

Question 13

IHC for mucinous cystic neoplasm of pancreas

Answer 13

IHC: Ovarian stroma stains- ER, PR, Inhibin, and Smooth muscle actin; Lining epithelium stains- cytokeratin, CEA and MUC5AC

Question 14

3 subtypes of IPMN

Answer 14

➢ Gastric type: Most common, resembles foveolar cells, usually with low-grade dysplasia and branch-duct involvement
➢ Intestinal type: Long papillae, tall, columnar epithelium, usually with low- or high-grade dysplasia and main-duct involvement
➢ Pancreatobiliary type: Complex branching papillae, resembles biliary epithelium, low cuboidal with amphophilic cytoplasm, usually with high-grade dysplasia and main-duct involvement

Question 15

Which IPMN subtype will most classically show high-grade dysplasia?

Answer 15

➢ Pancreatobiliary type: Complex branching papillae, resembles biliary epithelium, low cuboidal with amphophilic cytoplasm, usually with high-grade dysplasia and main-duct involvement

Question 16

IHC for IPMN

Answer 16

• IHC: Positive ductal markers: CK7, CK 19, CEA, CA19-9. Mucin glycoprotein (MUC) expression and CDX2 are useful to distinguish the subtypes
• Gastric type: MUC5AC+
• Intestinal type: MUC2+, CK20+, CDX2+, MUC5AC+
• Pancreatobiliary type: MUC1+, MUC5AC+, MUC6+

Question 17

Mutations and molecular for IPMN

Answer 17

*GNAS is the most specific mutation to IPMN
* KRAS mutations are the most common. GNAS mutations are also common and seem to be relatively unique to IPMNs
* RNF43 is the next common mutation seen
* TP53 and SMAD4 mutations are seen in those with invasive carcinoma