Context: Germline mutations in the aryl hydrocarbon receptor interacting protein gene (AIP) have been identified in young patients (age %30 years old) with sporadic pituitary macroadenomas. Otherwise, there are few data concerning the prevalence of multiple endocrine neoplasia type 1 (MEN1) mutations in such a population. Objective: We assessed the prevalence of both AIP and MEN1 genetic abnormalities (mutations and large gene deletions) in young patients (age %30 years old) diagnosed with sporadic and isolated macroadenoma, without hypercalcemia and/or MEN1-associated lesions. Design: The entire coding sequences of AIP and MEN1 were screened for mutations. In cases of negative sequencing screening, multiplex ligation-dependent probe amplification was performed for the detection of large genetic deletions. Patients and settings: One hundred and seventy-four patients from endocrinology departments of 15 French University Hospital Centers were eligible for this study. Results: Twenty-one out of 174 (12%) patients had AIP (nZ15, 8.6%) or MEN1 (nZ6, 3.4%) mutations. In pediatric patients (age %18 years old), AIP/MEN1 mutation frequency reached nearly 22% (nZ10/46). AIPmut and MEN1mut were identified in 8/79 (10.1%) and 1/79 (1.2%) somatotropinoma patients respectively; they each accounted for 4/74 (5.4%) prolactinoma (PRL) patients with mutations. Half of those patients (nZ3/6) with gigantism displayed mutations in AIP. Interestingly, 4/12 (33%) patients with non-secreting adenomas bore either AIP or MEN1 mutations, whereas none of the eight corticotroph adenomas or the single thyrotropinoma case had mutations. No large gene deletions were observed in sequencing-negative patients. Conclusion: Mutations in MEN1 can be of significance in young patients with sporadic isolated pituitary macroadenomas, particularly PRL, and together with AIP, we suggest genetic analysis of MEN1 in such a population.

Early surgical treatment is recommended in almost all patients after preoperative evaluation and detection of multifocal tumors. Surgical excision of small tumors was safe and without complication, but resection of Shamblin 3 tumors can be challenging. Routine preoperative embolization of carotid body paragangliomas is not required.

Comprehensive genetic analyses have identified germline and gene mutations as predominant causes of metastatic paraganglioma and pheochromocytoma. However, some suspicious cases remain unexplained. In this study, we performed whole-exome sequencing of a paraganglioma exhibiting an -like molecular profile in the absence of or mutations and identified a germline mutation in the gene, which encodes the mitochondrial 2-oxoglutarate/malate carrier. Germline mutations were identified in six other patients, five of whom had metastatic disease. These mutations were associated with loss of heterozygosity, suggesting that acts as a tumor-suppressor gene. Pseudohypoxic and hypermethylator phenotypes comparable with those described in - and-related tumors were observed both in tumors with mutated and in immortalized mouse chromaffin knockout cells generated by CRISPR-Cas9 technology. These data show that is a novel paraganglioma susceptibility gene for which loss of function correlates with metastatic presentation. A gene encoding a mitochondrial carrier is implicated in a hereditary cancer predisposition syndrome, expanding the role of mitochondrial dysfunction in paraganglioma. .

Half of the therapy-naive patients with MPP achieved stable disease at 1 year. In symptom-free patients with MPP, a wait-and-see antitumor policy seems appropriate as first line. Modality for a prospective follow-up is proposed.