The early diagnosis of multiple endocrine neoplasia type 1 (MEN 1): a case report

Endoscopic Ultrasound Features of Multiple Endocrine Neoplasia Type 1-Related versus Sporadic Pancreatic Neuroendocrine Tumors: A Single-Center Retrospective Study

AIM

Pancreatic neuroendocrine tumors (pNETs) can occur in patients with a familial syndrome either as multiple endocrine neoplasia type 1 (MEN-1) or as sporadic tumors. Endoscopic ultrasound (EUS) has become one of the first-line investigations for pNET characterization. The ultrasonographic features of pNETs may differ depending on the familial versus sporadic pathogenesis of the tumor. Therefore, the EUS findings could help and direct the definition of a pNET with an impact on the most appropriate diagnostic and therapeutic patient management.

METHODS

In this single-center retrospective study, we reviewed the EUS features of 94 pNETs from 37 MEN-1 patients and 15 pNETs from 11 sporadic disease patients at the time of their first EUS assessment. We analyzed the most relevant morphological and ultrasonographic characteristics of the tumors and compared the findings between the 2 patient groups.

RESULTS

Patients with MEN-1 more likely present with multiple pNETs than patients with sporadic disease. Sporadic pNETs are usually much bigger than those due to MEN-1. Moreover, pNETs are more heterogeneous in patients with sporadic disease than in those with MEN-1. No statistical difference with regard to definition of the margins, morphology, and vascularization of the pNETs appears between the 2 groups.

CONCLUSIONS

Patients with sporadic disease usually present with bigger and more heterogeneous pNETs than patients with MEN-1, who tend to present with a higher number of lesions. EUS can facilitate the precise characterization of a pNET, and the ultrasonographic features of the lesion can help and distinguish MEN-1-related versus sporadic disease.

Is Routine Screening of Young Asymptomatic MEN1 Patients Necessary?

BACKGROUND

Recent clinical practice guidelines recommend that routine screening of MEN1 mutation carriers should start at the age of 5 years. The occurrence of clinically relevant MEN1 organ manifestations in children (≤18 years) was evaluated.

METHODS

Two prospective collected databases of MEN1 patients (n = 166) who underwent annual screening were retrospectively analyzed for organ manifestations in MEN1 patients ≤18 years. The follow-up was based on the most recent screening examination until December 2015.

RESULTS

Twenty [11 females, 9 males, (12%)] of 166 MEN1 patients were diagnosed with at least one organ manifestation at age ≤18 years. The most frequent manifestation was mild asymptomatic pHPT (n = 9, 45%, age range 8-18 years). Eight (40%) young patients had pNENs (three non-functioning pNENs, five insulinomas, age range 9-18 years). All five insulinomas were diagnosed based on hypoglycemic symptoms. The other organ manifestations were asymptomatic pituitary adenomas in six patients (30%, age range 15-18 years) and a bronchial carcinoid in one 15-year-old patient. Only six (30%) patients ≤18 years had clinically relevant organ manifestations.

CONCLUSION

Symptomatic or severe manifestations in MEN1 patients rarely occur below the age of 16 years. With regard to psychological burden and cost-effectiveness, routine screening of asymptomatic MEN1 patients should be postponed at least until the age of 16 years.

Two novel mutations in the MEN1 gene in subjects with multiple endocrine neoplasia-1

Multiple endocrine neoplasia type 1 (MEN1) is characterized by parathyroid, enteropancreatic endocrine and pituitary adenomas as well as germline mutation of the MEN1 gene. We describe 2 families with MEN1 with novel mutations in the MEN1 gene. One family was of Turkish origin, and the index patient had primary hyperparathyroidism (PHPT) plus a prolactinoma; three relatives had PHPT only. The index patient in the second family was a 46-yr-old woman of Chinese origin living in Taiwan. This patient presented with a complaint of epigastric pain and watery diarrhea over the past 3 months, and had undergone subtotal parathyroidectomy and enucleation of pancreatic islet cell tumor about 10 yr before. There was also a prolactinoma. Sequence analysis of the MEN1 gene from leukocyte genomic DNA revealed heterozygous mutations in both probands. The Turkish patient and her affected relatives all had a heterozygous A to G transition at codon 557 (AAG-->GAG) of exon 10 of MEN1 that results in a replacement of lysine by glutamic acid. The Chinese index patient and one of her siblings had a heterozygous mutation at codon 418 of exon 9 (GAC-->TAT) that results in a substitution of aspartic acid by tyrosine. In conclusion, we have identified 2 novel missense mutations in the MEN1 gene.