Fig 2: Menin immunohistochemistry and LOH-analysis of 2 parathyroid tumor patients with a clinical suspicion of MEN1 syndrome and a MEN1 VUS mutation. One patient (patient 49) showed retained menin expression (A) and LOH analysis using a SNP array showed no copy number variation nor heterozygous loss of MEN1 (B). The second patient (patient 50) showed aberrant nuclear menin staining by immunohistochemistry (C) and a LOH analysis using an SNP array showed monosomy of chromosome 11, including heterozygous loss of MEN1 (D).

Fig 3: Menin immunohistochemical staining and LOH-analysis. A, Sporadic parathyroid tumor (patient 24) showing preserved nuclear menin expression by immunohistochemistry. B, MEN1 syndrome-related parathyroid tumor (patient 16) showing absent nuclear menin expression by immunohistochemistry. C, LOH analysis of patient 16, using SNP-array showing MEN1 LOH.

Fig 4: Menin immunohistochemistry and LOH-analysis of 2 parathyroid tumor patients with a clinical suspicion of MEN1 syndrome and a MEN1 VUS mutation. One patient (patient 49) showed retained menin expression (A) and LOH analysis using a SNP array showed no copy number variation nor heterozygous loss of MEN1 (B). The second patient (patient 50) showed aberrant nuclear menin staining by immunohistochemistry (C) and a LOH analysis using an SNP array showed monosomy of chromosome 11, including heterozygous loss of MEN1 (D).