Pathological differential diagnosis of solid-pseudopapillary neoplasm and endocrine tumors of the pancreas

Table 1 Clinical and pathological features of SPN and PET

Case No.	Sex/age (yr)	Tumor location	Size (cm)	Cystic or solid	H/N	PP areas
SPN group
1	F/17	Body	9.5	Cystic	Present	Present
2	F/19	Tail	6.0	Cystic	Present	Present
3	F/14	Head	8.0	Cystic	Present	Present
4	M/20	Body & tail	10.0	Cystic & solid	Present	Present
5	F/24	Head	10.0	Cystic	Present	Present
6	F/33	Body & tail	5.0	Solid	Absent	Present
7	F/21	Body & tail	20.0	Cystic & solid	Present	Present
8	M/43	Body	10.5	Cystic & solid	Present	Present
9	F/27	Tail	12.0	Cystic& solid	Present	Present
10	F/38	Unclear	19.5	Cystic & solid	Present	Present
PET group
11	F/16	Head	1.5	Solid	Absent	Absent
12	F/53	Body	2.0	Solid	Absent	Absent
13	M/44	Tail	1.5	Solid	Absent	Absent
14	F/40	Head	4.5	Solid	Absent	Absent
15	M/43	Head	3.0	Solid	Absent	Absent
16	F/49	Head	1.5	Solid	Absent	Absent
17	F/34	Head	2.0	Solid	Absent	Absent
18	F/46	Head	1.5	Solid	Absent	Absent
19	F/49	Tail	5.5	Solid	Absent	Absent
20	M/52	Head	3.0	Cystic & solid	Present	Absent
21	F/50	Tail	1.5	Solid	Absent	Absent
22	M/37	Tail	4.2	Cystic & solid	Present	Absent
23	F/45	Body	3.4	Solid	Absent	Absent
24	M/46	Tail	5.7	Cystic & solid	Present	Absent

H/N: Hemorrhage/necrosis; PP: Pseudopapillary; SPN: Solid-pseudopapillary neoplasm; PET: Pancreatic endocrine tumor.

Table 2 Immunohistochemical results of SPN and PET

Case No.	AACT	AAT	Vim	NSE	Syn	CgA	CK	EMA	Ins	Som	Glu	PP	E-cad	Beta	Ki-67 (%)
SPN group
1	+	+	+	-	-	-	-	+	-	-	-	-	-	N/C	> 1
2	+	+	+	+	+	-	+	+	-	-	-	-	-	N/C	> 1
3	+	+	-	+	-	+	-	-	-	-	-	-	-	N/C	> 1
4	+	+	-	+	+	-	-	-	-	-	-	-	-	N/C	> 1
5	+	+	+	+	+	-	-	+	-	-	-	-	-	N/C	> 1
6	-	+	+	+	+	-	+	-	-	-	-	-	-	N/C	> 1
7	+	+	+	+	-	+	-	-	-	-	-	-	-	N/C	> 1
8	+	-	+	-	+	-	-	-	-	-	-	-	-	N/C	> 1
9	-	+	-	-	-	-	+	-	-	-	-	-	-	N/C	> 1
10	+	-	-	-	+	+	+	-	-	-	-	-	-	N/C	2
PET group
11	-	-	-	+	+	-	+	+	+	-	-	-	+	C/M	> 1
12	-	-	-	+	+	+	-	+	+	+		-	+	C/M	> 1
13	-	-	-	+	+	+	-	-	+	-	-	-	+	C/M	> 1
14	-	-	+	+	+	+	+	+	-	-	-	-	+	C/M	> 1
15	-	-	-	+	+	+	+	+	-	-	+-	+	+	C/M	> 1
16	-	-	-	+	+	+	+	-	-	-	-	-	+	C/M	> 1
17	-	-	+	+	+	+	+	+	+	+	-	-	+	C/M	> 1
18	-	-	-	+	+	+	+	+	+	-	-	-	+	C/M	> 1
19	+	-	-	+	+	+	-	-	-	-	-	-	+	C/M	2
20	-	-	-	-	+	+	-	-	-	-	-	-	+	C/M	> 1
21	+	-	-	+	+	+	+	+	+	-	-	-	+	C/M	> 1
22	-	+	-	-	-	+	+	-	-	-	-	-	+	C/M	3
23	-	+	+	-	+	-	+	+	-	-	-	-	+	C/M	> 1
24	+	-	+	-	-	-	-	+	-	-	-	-	+	C/M	4

N/C: Nuclear & cytoplasm; C/M: Cytoplasm & membrane; AACT: α-1-Antichymotrypsin; AAT: α-1-Antitrypsin; Vim: Vimentin; NSE: Neuron-specific enolase; Syn: Synaptophysin; CgA: Chromogranin; CK: Cytokeratin; Ins: Insulin; Som: Somatostatin; Glu: Glucagon; E-cad: E-cadherin.

Table 3 The details of β-catenin gene exon 3 mutation in SPN

Case No.	Codon	Base substitution	Amino acid conversion
1	33	TCT→TGT	Ser→Cys
2	37	TCT→TAT	Ser→Tyr
3	34	GGA→GTA	Gly→Val
4		Wild type
5	32	GAC→TAC	Asp→Tyr
6	34	GGA→AGA	Gly→Arg
7	33	TCT→CCT	Ser→Pro
8	32	GAC→TAC	Asp→Tyr
9	32	GAC→GTC	Asp→Val
10	32	GAC→TAC	Asp→Tyr