PMC4398929_01
MRI of pelvis at the level of the bladder and rectum. Arrow: colovesicular fistula.
CRIPA2015-806310.001.jpg
PMC4398929_01_CRIPA2015-806310.001.jpg
fig1
MRI demonstrated the abnormalities stated above and suggested a mass near the colovesicular fistula (Figure 1).
Clusters and cords of medium-sized cells with small round to oval nuclei dispersed within the colonic mucosa (H&E, x200).
CRIPA2015-806310.002.jpg
PMC4398929_01_CRIPA2015-806310.002.jpg
fig2
These foci involved the mucosa and submucosa and were composed of small clusters of medium-sized cells with small round to oval nuclei containing fine chromatin with a salt and pepper appearance (Figures 2 and 3).
At high power, the cells contain fine chromatin. Nucleoli and mitoses are inconspicuous (H&E, x400).
CRIPA2015-806310.003.jpg
PMC4398929_01_CRIPA2015-806310.003.jpg
fig3
These foci involved the mucosa and submucosa and were composed of small clusters of medium-sized cells with small round to oval nuclei containing fine chromatin with a salt and pepper appearance (Figures 2 and 3).
Strong and diffuse immunoreactivity with synaptophysin confirms neuroendocrine differentiation (Synaptophysin, x200).
CRIPA2015-806310.004.jpg
PMC4398929_01_CRIPA2015-806310.004.jpg
fig4
By immunohistochemistry, the lesional cells were strongly and diffusely immunoreactive with synaptophysin and chromogranin (Figure 4).
The proliferation index was <2% (Ki-67, x200).
CRIPA2015-806310.005.jpg
PMC4398929_01_CRIPA2015-806310.005.jpg
fig5
The proliferative index, assessed with Ki-67, was less than 2% (Figure 5).