Thymic Carcinoid As The First Manifestation Of Multiple Endocrine Neoplasia Type 1 Syndrome: A Case Report And Review Of The Literature

Background: Multiple endocrine neoplasia type 1(MEN1)is a rare autosomal dominant genetic disease,which affects multiple endocrine organs and reduces life expectancy.Early diagnosis and treatment can reduces morbidity and improves disease outcomes.Patients with MEN1 usually present with primary hyperparathyroidism caused by multiple parathyroid tumors as their first manifestation,while thymic carcinoids as the first manifestation are rare.Thymic carcinoid account for 1-5% of MEN1 patients,which is the main cause of death of MEN1 patients.Case presentation: A 40-year-old male who suffered with thymic c arcinoid 10 years ago.After prolactinoma resection,severe hypoglycemia recurred during 2 years.Subsequent studies demonstrated hepatic metast atic pancreatic insulinoma and hyperparathyroidism.Genetic testing showe d the mutation of the MEN 1(c.378G>A;p.Trp126*)in the patient,his c hildren and two sisters,and GCKR(c.151C>T;p.Arg51*)gene in the patie nt and his children.The diagnosis of MEN1 was clear.The pathological d iagnosis of the neuroendocrine tumors(NET)of the pancreas with G2 g rading was characterized as adipose tissue infiltration and no intravascul ar emboli and nerve infiltration.In addition,NET of the liver with G2 grading were characterized as no intravascular emboli and nerve infiltrati on.Immunohistochemical staining showed Ckpan(+),Syn(+),Cg A(+),CD 56(+),PGP 9.5(+),p53(-)and Ki67-positive cells(8-10%)in N ET.The patient was in good health 1.5 years after operation.Conclusions:Patients with one endocrine tumor should be examined for other potential endocrine tumors and,if necessary,for genetic testi ng.It remains to be studied that the differences of surgical indications and postoperative efficacy between the MEN1-associated malignant insulin omas and sporadic malignant insulinomas.