We all know that Neuroendocrine Tumours (NETs) and their syndromes are complex but there is even more complexity to be found in a group of related disorders known as Multiple Endocrine Neoplasia (MEN). I recommend all NET patients should try to understand the basics of MEN and vice versa, particularly as both conditions seem to come with a plethora of endocrine related effects.
MEN patients will normally have a tumour in at least two endocrine glands – thus the terms ‘Multiple’ and ‘Endocrine’ (tumours can also develop in other organs and tissues). Neoplasia is just another name for tumour and these can be non-cancerous (benign) or cancerous (malignant) with the potential to metastasize.
MEN syndromes can comprise varying combinations of tumours and many will be aware of the tumour risks from family knowledge. So putting the heredity aspects to one side, it’s potentially an extremely challenging surveillance and subsequent diagnostic scenario if (and when) these risks are realised. To add to the complexity, some of the associated tumours can be sporadic (non hereditary) classic Neuroendocrine Tumours in various locations.
MEN is actually an umbrella term for a number of types (syndromes) of the disease – MEN1, MEN2a and 2b (2b was formerly MEN3). There’s a new kid on the block called MEN4 which is extremely rare.
In the most basic of terms regarding the relationship with tumours:
MEN1 seems to be centred on tumours of the parathyroid glands, the pituitary gland, and the pancreas (the 3 P’s).
MEN2a mainly focuses on medullary thyroid carcinoma, pheochromocytoma, parathyroid hyperplasia or adenomas (causing hyperparathyroidism), and occasionally cutaneous lichen amyloidosis.
MEN2b medullary thyroid carcinoma, pheochromocytoma, multiple mucosal neuromas and intestinal ganglioneuromas, and often a marfanoid habitus and other skeletal abnormalities.
MEN4 – A relatively new MEN variant and related to the CDKN1B gene, similar to MEN1 but normally only 2 of the 3 Ps, parathyroid and pituitary. Also referred to as MENX Possible association with tumors of the adrenals, kidneys, and reproductive organs.
What is particularly distinctive with MEN is that they are inherited disorders (familial). That means that they can be passed down in families, with each child of an affected parent having a 1 in 2 or 50% risk of inheritance. Consequently genetic screening/testing is normally undertaken in established MEN families and those at risk of MEN.
You may also have heard of other rare NETs with a familial aspect, in particular Pheochromocytomas (adrenal gland tumours) and Paragangliomas (outside the adrenal gland), Not all are inherited and I mention them because of the connection with MEN2a and 2b.
- AMEN Support where there is a useful Primer Leaflet
- A great video from Dr Mark Lewis who is an Oncologist and MEN patient. This is great as he speaks as both! Click here to watch
- More technical information can be found on the NIH site here including the genetic aspects.
- For patients, there is an excellent support group forum here – Join the AMEN Support patient support group.
I’m grateful to my friend and MEN patient Linda Hageman for supporting my blog activities and also for allowing me to join the AMEN support group to learn more. This is one of the friendliest and well run support groups I’ve seen. On this site, you will find Dr Mark Lewis, an Oncologist and MEN patient who supports Linda (who is a Nurse) with a ‘Ask the Doctor’ section on their website.
You may also enjoy my article on Genetics and Neuroendocrine Cancer.
Thanks for reading