Clinical implication of MEN1 mutation in surgically resected thymic carcinoid patients

Thymic carcinoid is a rare but very aggressive neuroendocrine tumour derived from the neuroendocrine system. Here we report a male patient with thymic atypical carcinoid. Though thymic carcinoid is relatively common, the gene sequencing profile was performed and the gene sequencing result indicated germline multiple endocrine neoplasia type 1 (MEN1) mutation and two somatic mutations on MEN1 gene and no copy number variation or fusion events were detected. It is well-known that the mutation of MEN1 is the typical manifestation of MEN1 syndrome, which is an autosome dominant disease that includes varying combinations of more than 20 endocrine and non-endocrine tumors. In the English literature, 7 cases of solitary thymic carcinoid harboring somatic variants in MEN1 are reported in the absence of other organs involvement as MEN1 syndrome presents. We summarized the clinical features and prognosis of this rare thymic tumor.