Multiple endocrine neoplasia (MEN) refers to a group of hereditary syndromes characterized by the occurrence of tumors in two or more endocrine glands. The tumors may be benign or malignant, functional (secreting active hormones with distinct clinical manifestations) or nonfunctional. They may appear simultaneously or sequentially, with variable intervals between occurrences. The severity of the condition, the progression of disease, and the clinical course exhibit significant heterogeneity. MEN is classified into two main types: multiple endocrine neoplasia type 1 (MEN1) and multiple endocrine neoplasia type 2 (MEN2). MEN2 is further divided into two subtypes: MEN2A and MEN2B. Additionally, there are mixed forms of MEN that do not fall into the categories of MEN1 or MEN2.
To be continued