MEN1 and parathyroid gland adenoma: To further investigate MEN1 loss of heterozygosity (LOH), we compared a MEN1 parathyroid adenoma (“Bern 3”, c.563G > C/p.W188S mutation) with a non-MEN1 parathyroid adenoma using a MEN1 specific and centromere 11 (C11) fluorescence in situ hybridization (FISH) probe.