Multiple endocrine neoplasia

Multiple endocrine neoplasia (MEN) is characterised by the occurrence of tumours involving 2 or more endocrine glands in a single patient.

MEN may be sporadic or inherited in an autosomal dominant pattern.

The subtypes of MEN are: 

• MEN 1: 
• Tumours of:
• Parathyroid – 95% 
• Pancreas – 40%- most commonly gastrinoma (leading to Zollinger-Ellison syndrome), second most common insulinoma
• Pituitary – 30% 
• Mutation on chromosome 11 of the gene which codes for menin 
• MEN 2: 
• MEN 2a: 
• Tumours of:
• Medullary thyroid 
• Parathyroid 
• Phaeochromocytoma 
• Caused by Ret gene on chromosome 10
• Commonest form of MEN 2 
• MEN2b
• Features may include:
• Medullary thyroid tumour
• Phaeochromocytoma 
• Marfanoid habitus 
• Mucosal neuromas 
• Megacolon 
• Caused by Ret gene on chromosome 10

Presentation is with the complications of the tumours, for example hypercalcaemia with parathyroid tumours or hypoglycaemia with insulinoma.

Treatment tends to be surgical.

References:

Marini, F. et al. Multiple endocrine neoplasia type 1. Orphanet J Rare Dis. 2006; 1:38. 

Marini, F. et al. Multiple endocrine neoplasia type 2. Orphanet J Rare Dis. 2006; 1:45. 

Thakker, R. Multiple endocrine neoplasia – syndromes of the twentieth century. J Clin Encdocrinol Metab. 1998; 83(8): 2617-2620.