TFF2 and neuroendocrine neoplasm: The diagnosis of this entity requires histologic evidence of a clear cell cytoplasm with an eccentric nucleus, positive IHC stains for pancytokeratin and other cytokeratins such as CK7, in addition to ruling out other pathologies such as neuroendocrine tumors and RCC with a negative stain for CG, SP, and Vimentin, respectively.