Imaging features of solid pseudopapillary tumor of the pancreas on multi-detector row computed tomography

Table 1 Imaging features of SPTs on MDCT in comparison with surgical and pathological results n (%)

Imaging features on MDCT	Surgical and pathological results
	Benign (n = 18)	Malignant or potentially malignant (n = 6)
Location
Head	8 (33.3)	3 (12.5)
Neck	1 (4.2)	0
Body	2 (8.3)	1 (4.2)
Tail	5 (20.8)	2 (8.3)
Body-neck	1 (4.2)	0
Body-tail	1 (4.2)	0
Size
< 6 cm	10 (41.7)	1 (4.2)
≥ 6 cm	8 (33.3)	5 (20.8)
Density
Cystic	5 (20.8)	0
Solid	3 (12.5)	2 (8.3)
Solid-cystic	10 (41.7)	4 (16.6)
With calcifications	3 (12.5)	2 (8.3)
Capsule
Intact	15 (62.5)	0
Un-intact	3 (12.5)	6 (25)
Enhancement
Mild	6 (25)	0
Moderate	9 (37.5)	3 (12.5)
Marked	3 (12.5)	3 (12.5)
Enhancing pattern and hemodynamics
Peripheral and persistent enhancement	17 (70.8)	6 (25)
Central and persistent enhancement	1 (4.2)	0
Pancreatic or peripancreatic invasion
Adjacent pancreatic invasion	3 (12.5)	6 (25)
Pancreatic duct dilatation	1 (4.2)	1 (4.2)
Peripancreatic fat invasion	1 (4.2)	6 (25)
Nearby vessels involvement	2 (8.4)	6 (25)
Direct invasion into adjacent organs	0	3 (12.5)
Regional lymph nodes metastasis	0	3 (12.5)
Liver metastasis	0	1 (4.2)

Table 2 Comparison of MDCT diagnosis and pathologic results in SPTs

MDCT	Pathologic results		Total
	Malignant or malignant potential	Benign
Malignant	5	3	8
Benign	1	15	16
Total	6	18	24

Kappa = 0.6, P < 0.05.

Table 3 Correlation between tumor size and aggressive behaviors in SPTs

Tumor size	Vascular involvement		Metastasis		Capsular invasion
	Positive	Negative	Positive	Negative	Positive	Negative
< 6 cm	1	10	0	11	0	6
≥ 6 cm	8	5	13	10	9	4

Fisher’s exact test: P = 0.013 for vascular involvement; P = 0.001 for capsular invasion.

¹2 cases with lymph node metastasis and 1 case with lymph node metastasis and hepatic metastasis.

Table 4 Vascular invasion on MDCT in comparison with surgical and pathological results in six malignant and two benign SPT cases

MDCT	Surgical and pathological results
	PV (n = 51)	SV (n = 5)	SMV (n = 5)	CA (n = 2)	CHA (n = 3)	PHA (n = 3)	SA (n = 3)	SMA (n = 3)
Axial images	3	1	2	0	3	3	1	0
CTA MIP images	5	3	5	1	3	3	42	3
MPVR images	5	3	4	1	3	3	3	3
A+C+M	5	5	5	2	3	3	3	3

¹indicating three malignant and two benign SPTs;

²one of four cases was overestimated; CTA: Computed tomography angiography; MIP: Maxiumum intensity projection; MPVR: Multiplanar volume reformation; A+C+M: Combination of axial images and CTA MIP and MPVR images. PV: Portal vein; SV: Splenic vein; SMV: Superior mesenteric vein; CA: Celiac artery; CHA: Common hepatic artery; PHA: Proper hepatic artery; SA: Splenic artery; SMA: Superior mesenteric artery.