These are a group of disorders where affected individuals develop tumours in two or more endocrine glands at the same time, making the affected glands overactive. With several endocrine systems being overactive, a diverse range of symptoms is seen. They are inherited disorders (inherited in an autosomal dominant pattern).
There are two main types of MEN syndrome:
This was first described by Wermer in 1954. It is a rare disorder, affecting approximately 0.25% of the population. It affects all age groups, with cases reported from 5-81 years of age. Clinical symptoms have normally appeared by the fifth decade of life.
It is characterised by the co-existence of:
More rarely tumours of the adrenal cortex, carcinoid tumours (special tumours, often arising in the gut - described in their own section) and lipomas (tumours of fat tissue) may also occur within MEN-1.
This syndrome was first described by Sipple in 1961. It is less common than MEN 1, but again affects all age groups with cases reported from 2-60 years of age. Symptoms develop less readily than in MEN 1 with 40% of people with the gene remaining asymptomatic at 70 years of age.
It is divided into two further sub-classes:
The most common variant of MEN 2. This is characterised by:
This has no parathyroid involvement and is characterised by:
The syndrome can occur with the only manifestation being medullary thyroid carcinoma.