MEN-1 Syndrome (Wermer Syndrome)

MEN-1 Syndrome (Wermer Syndrome)

•Autosomal Dominant syndrome

•2/1 lakh population Prevalence.

•80% cases have Truncated menin protein** and result in oncogenesis

Clinical Features:

•Affects 3 P- Parathyroid (90%-MC), Pituitary and Pancreas.

•90% have Hyperparathyroidism due to Multiglandular hyperplasia*

•2nd MC manifest is Neuroendocrine tumor of Pancreas and Duodenum.


•Carcinoids in Thymus and Bronchus

•Pituitary adenomas- MC prolactinoma (15%-30%)

•Male and Female equally affected.

•MC pancreatic tumor is Gastrinoma**

•MC cause of mortality in MEN-1 is NET from Duodenal and pancreatic

tumors or Intra thoracic carcinoids.

•MEN 1 manifests from age of 5 years*

•Biochemical surveillance to start at below given ages:

~5 years: Prolactin level

~8 years: PTH and Calcium Level

~20 years: Gastrin, Chromogranin, Glucagon and Proinsulin


•MC manifest in MEN -1

•Due to multiglandular hyperplasia**

•MC in 2nd decade*

•1st Biochemical abnormality noted is Hypercalcemia*

•Enlargement is asymmetrical**(fig 1)

•Treatment: 2 options:

~Total Parathyroidectomy with heterotopic implantation of one parathyroid in Brachioradialis muscle

~Subtotal (removal of 3 and half glands)- Advantages are single incision

and absence of transient Hypocalcemia which may be seen in Total Parathyroidectomy**

Entero Pancreatic NET:

•2nd MC manifest is NET of Duodenum and Pancreas. (30-80% incidence)

•NET in MEN-1 are multifocal usually.

•MC site in Intra duodenal mucosa > Pancreas.

•CT scan, EUS, Somatostatin receptor scintigraphy (SRS) are used to localize

the tumors.

•SASI – Selective arterial secretagogue Injection is Invasive but most


•Most common (40-60%) NET are Gastrinomas and of them about 80%

are malignant**

•Of the location- Pancreatic gastrinomas produce more of liver metastasis

compared to Duodenal Gastrinomas.

•Excision is the treatment for Gastrinomas.

•Insulinomas are very less in incidence (10-25%)

•Only 10% of insulinomas are malignant.

Pituitary Adenomas:

•Anterior pituitary adenomas are 15-30% incidence in MEN-1

•MC Pituitary adenoma is Prolactinoma**-

•Clinical features: Amenorrhea, galactorrhea, hypogonadism in males*

•Acromegaly and Cushing Disease seen

Other Lesions:

•Type 2 Gastric Carcinoids

•Thymic Carcinoids

•Bronchial Carcinoids


•Facial angiofibromas



•Ependymomas of CNS

•Adreno cortical nodules and Bilateral adrenal hyperplasia (30%)