MEN1 and parathyroid gland adenoma: The ratio of menin-positive cells to menin-negative cells was found to be 90% for normal pancreatic acinar cells, 35% for duodenal NETs, 12% for parathyroid adenomas, 11% for pulmonary NETs, 9% for pancreatic NETs, and 0.01% for adrenocortical adenoma (myelolipoma).