Multiple Endocrine Neoplasias

Snapshot

A 38-year-old women presents to the emergency department with 1 day of severe flank pain. She also notes that she has had intermittent watery diarrhea for the past few weeks. On physical exam the patient has mild abdominal tenderness to palpation, particularly in the epigastric region and upper left quadrant, as well as costovertebral angle (CVA) tenderness. Lab studies show hypercalcemia and an ultrasound shows the presence of a kidney stone. (Multiple endocrine neoplasia [MEN] type I)

Introduction

Overview
- cancer syndrome with severate associated endocrine neoplasias
- 3 MEN types
  - MEN I
  - MEN IIA
  - MEN IIB
Genetics
- All MEN syndromes haveautosomal dominant inheritance
  - MEN1 gene located on chromosome 11
  - RET gene located on chromosome 10
Epidemiology
- prevalence
  - MEN I: 1 in 50,000
  - MEN II: 1 in 30,000
Prognosis
dependent on MEN type and which neoplasias occur in individual patient

Classification

Presentation

Imaging

Ultrasound of neck
- indications
  - patient with dysphagia or hoarseness
- findings
  - thyroid nodule
    - follow up with thyroid scintigraphy (radioactive iodine uptake scan)
Magnetic resonance imaging (MRI) or computed tomography (CT) scan of abdomen
- indications
  - patient with symptoms consistent with pheochromocytoma
- findings
adrenal gland mass

Studies

TSH levels
- to evaluate thyroid function
  - decreased TSH more concerning for malignancy
Serum calcitonin
- tumor marker for medullary thyroid cancer
Free serum metanephrine level
- elevated in pheochromocytoma
- follow up with 24-hour urin collection
  - increased urine metanephrines
  - elevated vanillyl mandelic acid (due to breakdown of norepinephrine and epinephrine)
Serum PTH and calcium levels
- elevated in parathyroid tumor
Serum glucose
- elevated in glucagonoma
- decreased in insulinoma
Serum glucagon
- elevated in glucagonoma
Serum insulin and C-peptide
- elevated in insulinoma
Serum gastrin
increased in gastrinoma

Treatment