PMC3572682_01
CT scan of abdomen and pelvis with contrast in (a) axial view and (b) coronal view showed well-defined 4.5 cm enhancing mass of mesocolon which was located anterior to descending duodenum, posterior to gastric antrum, and just medial to the hepatic flexure of colon.
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fig1
CT scan of abdomen and pelvis with contrast was performed to further evaluate the mass which showed well-defined 4.5 cm enhancing mass of mesocolon which was located anterior to descending duodenum, posterior to gastric antrum, and just medial to the hepatic flexure of colon (Figure 1).
(a) Clusters of cells surrounded by reticulin fibrosis known as Zellballen arrangement, typical of paraganglioma. (b) CD34 immunostain marking the numerous small capillaries in the tumor. (c) Chromogranin A immunohistochemical stain.
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fig2
This appearance is known as Zellballen arrangement, which is typical of paraganglioma (Figure 2(a)). The tumor was highly vascular in nature as highlighted by the CD34 immunostain (Figure 2(b)). AE1/AE3 cytokeratin and strongly immunoreactive for neuroendocrine markers CD56, chromogranin A (Figure 2(c)), and synaptophysin. Additional immunostains were performed to rule out carcinoid tumors and pheochromocytoma. 