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liver. Additional distinguishing feature in MEN1-related gastrinoma is the higher
incidence of concurrent gastric carcinoids as compared to sporadic gastrinoma.- How to manage a patient with gastrinoma in MEN1 syndrome?
Duodenal gastrinomas are usually small, but multiple; therefore, surgical cure
is usually difficult. Whipple’s pancreaticoduodenectomy results in cure rate of
65 %, but it is associated with higher operative mortality and long-term compli-
cations which include weight loss, diabetes mellitus, and malabsorption. Hence,
medical treatment is preferred which includes proton pump inhibitors and
somatostatin analogues, and streptozotocin-based chemotherapy in those with
metastatic disease. Though pancreatic gastrinomas are rare, but tumor size
>2 cm mandates surgical resection.- What are the characteristics of nonfunctioning pancreatic neuroendocrine
tumor in MEN 1 syndrome?
Nonfunctioning pancreatic neuroendocrine tumor (NET) is present in 20–55 %
of patients with MEN1 syndrome, and is increasingly recognized with better
imaging modalities. These tumors are usually recognized late in the course of
disease due to the absence of clinical manifestations. The majority of these
tumors are malignant and result in high morbidity and mortality. Endoscopic
ultrasound is the most sensitive modality to localize these pancreatic neuroen-
docrine tumors, whereas somatostatin receptor scintigraphy is useful to detect
metastatic disease. Surgical resection is recommended for tumor >1 cm in size
or tumor <1 cm but rapidly growing (doubling of tumor size over 3–6 months
interval). Tyrosine kinase inhibitors and mTOR inhibitor (mammalian target of
rapamycin) have been found to be useful.- What is MEN1 gene?
MEN1 is a tumor suppressor gene which is located on chromosome 11q13. It
consists of 10 exons which encodes 610 amino acid protein termed as Menin
that regulates transcription, genome stability, cell division, and proliferation.
Inheritance of a germ-line MEN1 mutation predisposes an individual to develop
a tumor after acquisition of somatic mutation which may be a point mutation or
more commonly a deletion. This results in loss of heterozygosity in the involved
tissue, thereby leading to tumor formation (Knudson hypothesis). The first-
degree relatives of the patients with MEN1 have 50 % risk of developing the
disease and can often be identified by MEN1 mutational analysis.11 Multiple Endocrine Neoplasia