Multiple endocrine neoplasia type 1 (MEN-1) is one of a group of disorders, the multiple endocrine neoplasias, that affect the endocrine system through development of neoplastic lesions in pituitary, parathyroid gland and pancreas. It was first described by Paul Wermer in 1954. Signs and symptoms
Parathyroid
Hyperparathyroidism is present in ≥ 90% of patients. Asymptomatic hypercalcemia is the most common manifestation: about 25% of patients have evidence of nephrolithiasis or nephrocalcinosis. In contrast to sporadic cases of hyperparathyroidism, diffuse hyperplasia or multiple adenomas are more common than solitary adenomas. Pancreas
Pancreatic islet cell tumors are today the major cause of death in persons with MEN-1. Tumors occur in 60-80% of persons with MEN-1 and they are usually multicentric. Multiple adenomas or diffuse islet cell hyperplasia commonly occurs. About 30% of tumors are malignant and have local or distant metastases. About 10-15% of islet cell tumors originate from a β-cell, secrete insulin (insulinoma), and can cause fasting hypoglycemia. β-cell tumors are more common in patients < 40 years of age. Most islet cell tumors secrete pancreatic polypeptide, the clinical significance of which is unknown. Gastrin is secreted by many non–β-cell tumors (increased gastrin secretion in MEN 1 also often originates from the duodenum). Increased gastrin secretion increases gastric acid, which may inactivate pancreatic lipase, leading to diarrhea and steatorrhea. Increased gastrin secretion also leads to peptic ulcers in > 50% of MEN 1 patients. Usually the ulcers are multiple or atypical in location, and often bleed, perforate, or become obstructed. Peptic ulcer disease may be intractable and complicated.
A lobulation is an appearance resembling lobules. For instance, the thyroid gland may become large and lobulated in Hashimotos thyroiditis.Fetal lobulation, also known as fetal lobation, of the kidney is evident on scanning. Fetal lobation is a normal stage in the development of the kidney. In the adult a normal anatomic variant is that of persistent fetal lobulation of the kidney that may be mistaken for a tumour. See also
Lobation


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