Taking into account that the morphology of oncocytes is basically the same in hyperplastic nodules and in adenomas, we tried to investigate immunohistochemically if there is any difference in the expression of previously used proteins in oncocytic neoplasms, such as b-catenin [9], Cyclin D1, p53, and Ki67 [10], without any significant result. The gene discussed is TP53; the disease is adenoma.