Multiple Endocrine Neoplasia Flashcards
Definition
An autosomal dominant condition characterised by a predilection to develop tumours of endocrine glands.
Aetiology/Risk factors
· Autosomal dominant inheritance
· Patterns of features:
o MEN 1 · Pituitary adenomas · Parathyroid tumours · Pancreatic islet-cell tumours (and other endocrine tumours of the gastroenterohepatic tract e.g. gastrinomas) · Fascial angiofibromas and collagenomas
o MEN 2a
· Parathyroid tumours
· Medullary thyroid cancer
· Phaeochromocytomas
o MEN 2b
· Same as MEN 2a
· Marfanoid appearance
· Neuromas of the GI tract
Epidemiology
VERY RARE
Presenting signs and symptoms (MEN 1)
o Age of onset of tumours is usually teenage years
o However, symptoms of the tumours may not become apparent for years
o Diagnosis is commonly made in the 4th decade of life
o Symptoms and signs are dependent on the organs affects:
· Hyperparathyroidism –> symptoms of hypercalcaemia + nephrolithiasis
· Hypergastrinaemia –> Zollinger-Ellison syndrome
· Hyperinsulinaemia –> hypoglycaemia
· Hyperprolactinaemia –> amenorrhoea
· Hypersomatotrophinaemia –> acromegaly
o Pituitary tumours may cause visual defects
Presenting signs and symptoms (MEN 2)
o Symptoms of medullary thyroid cancer, hyperparathyroidism or phaeochromocytoma
o Medullary thyroid cancer symptoms: · Hypertension · Episodic sweating · Diarrhoea · Pruritic skin lesions · Lump in the neck
o Hypercalcaemia symptoms: · Constipation · Polyuria/polydipsia · Depression · Kidney stones · Fatigue
Investigations (MEN 1)
o Screening first or second degree relatives
o Hormone hypersecretion blood tests
o DNA testing
Investigations (MEN 2)
o Phaeochromocytoma test - 24 hr urine metanephrines
· Can be followed by abdominal MRI
o Medullary thyroid cancer test - elevated calcitonin concentration
· Can also be investigated with ultrasound and FNA
o Parathyroid tumours - simultaneously elevated Ca2+ and PTH
