Does Computed Tomography Have the Ability to Differentiate Aggressive From Nonaggressive Solid Pseudopapillary Neoplasm?

Abstract

Objective: The aim of the study was to assess the ability of contrast-enhanced computed tomography (CECT) to differentiate aggressive from nonaggressive solid pseudopapillary neoplasms (SPNs).

Materials and methods: Forty treatment-naive patients with pathologically proven pancreatic SPNs were included. Imaging characteristics were determined by consensus of 3 radiologists blinded to histopathologic aggressiveness. All patients underwent 4-phase CECT using a pancreatic protocol. The regions of interest of the tumor and the normal pancreas were documented on all phases. Lymph nodes were considered metastatic if greater than 1.0 cm in short-axis diameter.Fisher exact and Wilcoxon rank-sum tests were used to compare between aggressive and nonaggressive tumors.

Results: No significant difference was noted between imaging covariates, such as internal hemorrhage, calcification, wall thickness perceptibility, vascular invasion, margins, cystic component, and pancreatic and biliary ductal dilation. Tumors with greater than 62.5 Hounsfield units and progressive enhancement during the delayed phase had aggressive characteristics (P = 0.03).

Conclusions: On delayed phase CECT, pathologically aggressive SPNs may show greater enhancement than nonaggressive SPNs.

Fig. 1

Of solid area of the tumor shows tumor arranged in sheets and is composed of round to ovoid neoplastic cells with homogenous to finely stippled chromatin and occasional small nucleoli. Grooves, a characteristic feature of SPN nuclei, are seen (arrow). The cytoplasm is eosinophilic with occasional vacuolization (hematoxylin and eosin, 9400) (a) Hemotshows a partial psudocapsule(arrow) around the tumor adjacent to the normal pancreas. (b) shows a tumor ble cells surrounding the nerve (light pink ovoid structure) representing perineural invasion(c ) shows the tumor (arrow ) extending into the addjacent pericolonic fat. (d) Blue cells representing the tumor extend into the a small vascular space containing tumor (arrow) representing lymphovascular invasion

Fig. 1

Of solid area of the tumor shows tumor arranged in sheets and is composed of round to ovoid neoplastic cells with homogenous to finely stippled chromatin and occasional small nucleoli. Grooves, a characteristic feature of SPN nuclei, are seen (arrow). The cytoplasm is eosinophilic with occasional vacuolization (hematoxylin and eosin, 9400) (a) Hemotshows a partial psudocapsule(arrow) around the tumor adjacent to the normal pancreas. (b) shows a tumor ble cells surrounding the nerve (light pink ovoid structure) representing perineural invasion(c ) shows the tumor (arrow ) extending into the addjacent pericolonic fat. (d) Blue cells representing the tumor extend into the a small vascular space containing tumor (arrow) representing lymphovascular invasion

Fig. 1

Of solid area of the tumor shows tumor arranged in sheets and is composed of round to ovoid neoplastic cells with homogenous to finely stippled chromatin and occasional small nucleoli. Grooves, a characteristic feature of SPN nuclei, are seen (arrow). The cytoplasm is eosinophilic with occasional vacuolization (hematoxylin and eosin, 9400) (a) Hemotshows a partial psudocapsule(arrow) around the tumor adjacent to the normal pancreas. (b) shows a tumor ble cells surrounding the nerve (light pink ovoid structure) representing perineural invasion(c ) shows the tumor (arrow ) extending into the addjacent pericolonic fat. (d) Blue cells representing the tumor extend into the a small vascular space containing tumor (arrow) representing lymphovascular invasion

Fig. 1

Of solid area of the tumor shows tumor arranged in sheets and is composed of round to ovoid neoplastic cells with homogenous to finely stippled chromatin and occasional small nucleoli. Grooves, a characteristic feature of SPN nuclei, are seen (arrow). The cytoplasm is eosinophilic with occasional vacuolization (hematoxylin and eosin, 9400) (a) Hemotshows a partial psudocapsule(arrow) around the tumor adjacent to the normal pancreas. (b) shows a tumor ble cells surrounding the nerve (light pink ovoid structure) representing perineural invasion(c ) shows the tumor (arrow ) extending into the addjacent pericolonic fat. (d) Blue cells representing the tumor extend into the a small vascular space containing tumor (arrow) representing lymphovascular invasion

Fig. 2

17-year-old female with epigastric pain and solid pseudopapillary neoplasm in the head of the pancreas. The noncontrast axial (a) arterial (b) portal venous (c) and delayed phase of contrast images show a pathologically non aggressive well circumscribed mass (arrow) in the pancreatic head.

Fig. 2

17-year-old female with epigastric pain and solid pseudopapillary neoplasm in the head of the pancreas. The noncontrast axial (a) arterial (b) portal venous (c) and delayed phase of contrast images show a pathologically non aggressive well circumscribed mass (arrow) in the pancreatic head.

Fig. 2

17-year-old female with epigastric pain and solid pseudopapillary neoplasm in the head of the pancreas. The noncontrast axial (a) arterial (b) portal venous (c) and delayed phase of contrast images show a pathologically non aggressive well circumscribed mass (arrow) in the pancreatic head.

Fig. 2

17-year-old female with epigastric pain and solid pseudopapillary neoplasm in the head of the pancreas. The noncontrast axial (a) arterial (b) portal venous (c) and delayed phase of contrast images show a pathologically non aggressive well circumscribed mass (arrow) in the pancreatic head.

Fig. 3

58-year-old male with an incidental pancreatic solid pseudopapillary neoplasm. The noncontrast axial {29HU} (a) arterial {59HU}(b) portal venous {72HU} (c) and delayed phase {85 HU} of contrast images show a pathologically aggressive mass (arrow) in the pancreatic head. The tumor has a central area of low attenuation and has eccentric calcifications as seen on the non contrast image (a).

Fig. 3

58-year-old male with an incidental pancreatic solid pseudopapillary neoplasm. The noncontrast axial {29HU} (a) arterial {59HU}(b) portal venous {72HU} (c) and delayed phase {85 HU} of contrast images show a pathologically aggressive mass (arrow) in the pancreatic head. The tumor has a central area of low attenuation and has eccentric calcifications as seen on the non contrast image (a).

Fig. 3

58-year-old male with an incidental pancreatic solid pseudopapillary neoplasm. The noncontrast axial {29HU} (a) arterial {59HU}(b) portal venous {72HU} (c) and delayed phase {85 HU} of contrast images show a pathologically aggressive mass (arrow) in the pancreatic head. The tumor has a central area of low attenuation and has eccentric calcifications as seen on the non contrast image (a).

Fig. 3

58-year-old male with an incidental pancreatic solid pseudopapillary neoplasm. The noncontrast axial {29HU} (a) arterial {59HU}(b) portal venous {72HU} (c) and delayed phase {85 HU} of contrast images show a pathologically aggressive mass (arrow) in the pancreatic head. The tumor has a central area of low attenuation and has eccentric calcifications as seen on the non contrast image (a).

Fig. 4

Shows a Box plot of the Hounsfield values on delayed phase of contrast plotted against aggressive vs nonaggressive pathology. The boxplots were overlaid with the actual data points (blue). To avoid overlap of data points with same value, the data points were scattered horizontally (jittered). In the Box-and-whisker plot, the ends of the box represent the 25th and 75th quantiles. The line within the box represents the median sample value. The red diamond shape represents the mean. The difference between the 25th and 75th quantiles is called the interquartile range (IQR). The lower whisker extend from the lower end of the box to the minimum value that is greater than or equal to the 25th quartile minus 1.5 time the IQR, and the upper whisker extend from the upper end of the box to the maximum value that is less than or equal to the 75th quartile plus 1.5 times the IQR.

Figure 5

Enhancement patterns of pathologically aggressive and nonaggressive solid pseudo papillary tumors (SPN) of the pancreas

Fig. 6

Kaplan Myer survival curves shows survival in all patients with solid speudopapillary tumors. Number of death = 3 and number of censored = 40. Survival time for the three patients who died were 6, 13, and 15 months.