"Fun Facts"
Why is MEN2B prognosis worse than MEN2A?
MEN2B has much higher rate of invasive C cell disease and much lower success rate with surgical cure. Medullary thyroid cancer is significantly more aggressive in 2B and the most common COD
Most common panctretic islet tumour in MEN1
Non functioning (up to 80%) then gastrinoma (54%)
Genes implicated in MEN1 and MEN 2
MEN1 (menin), RET
Gastrinoma lab value for diagnosis, confirmatory test
Gastrin >1000 diagnosis
Gastrin 200-1000 secretin stim test if rise in gastrin >100 pg/dL confirms gastrinoma
Treatment for hyperPTH in MEN
Often require 3.5 gland or 4 gland with reimplantation as commonly have 4 gland hyperplasia
Number one cause of death in MEN patients
Previously was endocrine overproduction but with medication advancements it is now maliganancy
Surveillance interval for pheochromocytoma in MEN2
yearly biochemical testing
Inheritance patterns of MEN 1, MEN2
All autosomal dominant
Confirmatory value for prolactinoma
PL >200ng/ml
Treatment of pituitary tumors in MEN
Prolactinoma: Dopamine agonist
GH secreting: Somatostatin analog
Transphenoidal surgery usually reserved for medically resistant
What are the components of MEN1, 2A, 2B?
1- pituitary, parathyroid, pancreat
2A- PTH, Medullary thyroid, Pheo
2B- Medullary thyroid, marfanoid neuromas, pheo
First presenting symptom in up to 85% of cases of MEN1
Hypercalcemia
What gene is in MEN 4?
CDKN1B
causes parathyroids, pancreatic, pituitary like in MEN1 also AD
Localization techniques for: Gastrinoma, glucagonoma, non functioning pancreatic tumour
radiolabelled octreotide scan (insulinomas will not show up_
When is prophylactic thyroidectomy recommended for MEN2a and MEN2b
MEN2A before age 5
MEN2B before age 1
What is the other name for MEN2A
Sipple syndrome (RIP)
Most common presenting manifestations of MEN2
Medullary thyroid cancer (100% penetrance), pheo (50% penetrance)
Type of mutation in MEN1/MEN2
MEN 1- loss of function MEN1 tumour suppressor gene
MEN 2- activating mutation in RET oncogene
Diagnostic values for insulinoma
Insulin level >6 uU/mL
elevated C peptide
How can you manage PNETs with metastasis to the liver or other locoregional mets
Metastatectomy or ablation with TACE
What famous president was theorized to have MEN2 (though probably did not)
Abraham Lincoln
Indications for PTH surgery in MEN1
symptomatic hyperparathyroidism, serum calcium greater than 1 mg/dL above normal, osteoporosis, nephrolithiasis, 24-hour urine calcium greater than 400 mg/dL, and age younger than 50 years.
Do not need imaging prior to resection. Must do BL exploration
Who gets genetic testing for MEN syndrome?
2+ classic MEN asssociated tumours
Single MEN associated tumour in first degree relative
Clinical features strongly suggestive of MEN (ex mucosal neuromas)
Pheochromocytoma workup
Plasma Metanephrines (very high = diagnosis confirmed)
High normal-> clonidine suppression test
if abnormal CST CT/MRI of abdomen/pelvis if + mass confirm with MIBG or PET. If no abdominal mass MIBG/PET or whole body MRI
When to resect non functional PNET? Functional PNET?
Non functional >2cm
Functional: Resect at any size except for insulinoma and gastrinoma <2cm can be enucleated