<prompt> Zellballen pattern seen in:Carotid body tumorLymphoepithelial cystCholesteatomaThyroglossal cyst  <response>: Zellballen pattern: Contain nest of sustentacular cells chief cells with pale eosinophilc staining Seen in tumors of chromaffin cells, i.e pheochromocytoma Paraganglioma carotid body tumor. Most common location of these tumors is within adrenal medulla,where they give rise to pheochromocytomas approximately 70 of extra-adrenal paragangliomas occur in head neck region. 