MEN1 and multiple endocrine neoplasia type 1: Hence, the evaluation of menin expression by immunohistochemistry may be an adjunct to the diagnosis of MEN1 syndrome patients.14 The correlation between loss of menin expression and MEN1 mutations in the setting of MEN1 syndrome has been shown in pancreatic tumors.14,15 Studies by, Alvelos et al,16 Bhuiyan et al,17 and Grolmusz et al,18 applied menin immunohistochemistry on sporadic and MEN1 syndrome-related parathyroid tumors.