PMC3548394_01
Composite photomicrographs of the tumor showing epithelioid cells arranged in a group with granular chromatins (a, FNA Pap stain, x40 Obj.); pleomorphic nuclei with nucleoli (b, FNA Diff-Quick stain, x100 Obj.); and cells with positive staining for synaptophysin (c, FNA, x100 Obj.). The histological section of the tumor (d, H and E, x40 Obj.) shows epithelioid or chief cells which are arranged in a pseudoalveolar pattern (Zellballen) nested in a vascular stroma which were positive for synaptophysin but negative for cytokeratin. Hyperchromatic spindle shaped sustentacular cells are at the periphery of the chief cell nests (arrows). They were only positive for S-100
CJ-9-26-g001.jpg
PMC3548394_01_CJ-9-26-g001.jpg
F1
The atypical cells showed enlarged nuclei with variably granular chromatin, occasional nucleoli, anisonucleosis, and scant delicate cytoplasm [Figure 1a and b]. The positive immunostain of the cells for synaptophysin [Figure 1c] was compatible with a tumor of neuroendocrine origin. Histological evaluation of the surgical specimen [Figure 1d] showed epithelioid cells arranged in an alveolar pattern in nests surrounded by capillary networks.