Evolution of Our Understanding of the Hyperparathyroid Syndromes: A Historical Perspective.

We review advancing and overlapping stages for our understanding of the expressions of six hyperparathyroid (HPT) syndromes: multiple endocrine neoplasia type 1 (MEN1) or type 4, multiple endocrine neoplasia type 2A (MEN2A), hyperparathyroidism-jaw tumor syndrome, familial hypocalciuric hypercalcemia, neonatal severe primary hyperparathyroidism, and familial isolated hyperparathyroidism. During stage 1 (1903 to 1967), the introduction of robust measurement of serum calcium was a milestone that uncovered hypercalcemia as the first sign of dysfunction in many HPT subjects, and inheritability was reported in each syndrome. The earliest reports of HPT syndromes were biased toward severe or striking manifestations. During stage 2 (1959 to 1985), the early formulations of a syndrome were improved. Radioimmunoassays (parathyroid hormone [PTH], gastrin, insulin, prolactin, calcitonin) were breakthroughs. They could identify a syndrome carrier, indicate an emerging tumor, characterize a tumor, or monitor a tumor. During stage 3 (1981 to 2006), the assembly of many cases enabled recognition of further details. For example, hormone non-secreting skin lesions were discovered in MEN1 and MEN2A. During stage 4 (1985 to the present), new genomic tools were a revolution for gene identification. Four principal genes ("principal" implies mutated or deleted in 50% or more probands for its syndrome) (MEN1, RET, CASR, CDC73) were identified for five syndromes. During stage 5 (1993 to the present), seven syndromal genes other than a principal gene were identified (CDKN1B, CDKN2B, CDKN2C, CDKN1A, GNA11, AP2S1, GCM2). Identification of AP2S1 and GCM2 became possible because of whole-exome sequencing. During stages 4 and 5, the newly identified genes enabled many studies, including robust assignment of the carriers and non-carriers of a mutation. Furthermore, molecular pathways of RET and the calcium-sensing receptor were elaborated, thereby facilitating developments in pharmacotherapy. Current findings hold the promise that more genes for HPT syndromes will be identified and studied in the near future. © 2018 American Society for Bone and Mineral Research.

Thymic and Bronchial Carcinoid Tumors in Multiple Endocrine Neoplasia Type 1: The Mayo Clinic Experience from 1977 to 2013.

The clinical features of thymic carcinoid (TC) and bronchial carcinoid (BC) tumors as part of multiple endocrine neoplasia type 1 (MEN1) have been rarely described and their importance in clinical practice is debated. The objective of this study was to describe the clinical presentation and outcome of this uncommon manifestation of MEN1 in a tertiary care center setting. We present the clinical features of patients with MEN1 and either TC or BC evaluated at the Mayo Clinic from 1977 to 2013. A total of 348 patients with MEN1 were evaluated and the prevalence of TC was 2.0% (n = 7) and of BC 4.9% (n = 17). The majority of the patients with BC were men (61%) diagnosed on routine screening (77%) and BC was not the confirmed cause of death in any patient. In contrast, TC patients were all men and during follow-up 43% died due to TC complications. We conclude that TC and BC tumors are uncommon, but important components of MEN1. BC were most commonly diagnosed during routine screening and associated with an indolent course. TC were predominantly seen in men and associated with a more aggressive behavior.

[Diagnostic and therapeutic strategies in Zollinger-Ellison syndrome associated with multiple endocrine neoplasia type I (MEN-I): experience of the Zollinger-Ellison Syndrome Research Group: Bichat 1958-1999]. / Stratégie diagnostique et thérapeutique du Syndrome de Zollinger-Ellison associé à une néoplasle endocrine multiple de type I (NEM I): l'expérience du Groupe d'Etudes et de Recherches sur le Syndrome de Zollinger-Ellison (GRESZE): Bichat 1958-1999.

About 25% of patients with ZES have MEN 1. Except diarrhoea, less frequent in patients with ZES-MEN 1 than in sporadic ZES, and specific MEN 1-related signs, clinical characteristics are similar in both ZES types. Acid output and gastrin levels are also similar whether in the basal state or after secretin stimulation. Primary hyperparathyroidism (PHPT) exists in the majority of ZES-MEN 1 patients, 30% have pituitary adenoma (prolactinomas for half), 30% adrenal involvement, 25 to 30% have EC-Lomas; bronchial and thymic carcinoids have probably been underevaluated. Gastrinomas are multiple predominantly located in the duodenal wall, but also in the pancreas in association with clinically silent endocrine tumors. The spread of the disease: metastases to the liver (LM), mediastinum, bones, is evaluated at best by Octreoscan. Endoscopic ultrasonography evaluates the number, size and anatomical characteristics of gastrinomas. Patients without LM have an excellent prognosis. Surgery never cures ZES, but is necessary in case of associated life-threatening condition such as insulinoma and has been advocated to prevent LM development in patients with large pancreatic tumor(s). However although, indeed, the size of the tumor, when located in the pancreas > 3 cm, favours metachronous LM occurrence, surgery, in our experience, has not been able to prevent LM development. Hepatic malignancies remain however the most pejorative prognostic determinant for survival and raise the most difficult therapeutic challenge. Surgery is the best option whenever feasible; specific chemotherapy and chemo-embolisation have not conclusively achieved definite successes. Long-term octreotide treatment, however, has been shown recently to obtain tumour stabilisation. Internal irradiation with 90 Ytrium-labelled octreotide is a new promising option, presently under evaluation (Novartis European trial). Preliminary results are promising.

[Pituitary pathology and MEN 1]. / Pathologie hypophysaire et NEM 1.

Multiple Endocrine Neoplasia type 1 (MEN 1) is an autosomal dominant syndrome characterized by neoplasia of the parathyroid glands, the endocrine pancreas and the anterior pituitary gland. Recently the identification on chromosome 11 (locus q13) of the gene responsible for MEN 1 has allowed direct genetic diagnosis of MEN 1-affected family members. To date almost 300 families have been described and genetically characterized. The genetic etiology of most pituitary tumours remains unknown. Pituitary adenomas can develop sporadically or as a part of multiple endocrine neoplasia type 1. In this review, the recently published data on the pathology of the MEN 1 syndrome will be summarized. The clinical, morphological and genetic aspects of sporadic and MEN 1-associated pituitary adenomas will be outlined.