PHEOCHROMOCYTOMA AND

HYPOGLYCEMIA

Lewis C. Weger, MPAS, PA-C

Principles of Clinical Medicine

OBJECTIVES Define Pheochromocytoma

Describe the Signs and Symptoms of Pheochromocytoma

Discuss the Work-up and Treatment of Pheochromocytoma

OBJECTIVES Define Hypoglycemia Discuss the Clinical Signs and

Symptoms of Hypoglycemia Discuss the Work-up and

Treatment of Hypoglycemia Discuss Reactive (Post-prandial)

Hypoglycemia Compare true Hypoglycemia to

Facticious Hypoglycemia

PHEOCHROMOCYTOMA

• Pheochromocytoma• Paroxysmal Hypertension in the

young to mid-adults predominantly

• Etiology• Tumor of the adrenal medulla (90%)– ~ 80% are unilateral and solitary– excess epinephrine production– excess Norepinephrine production– ~ 10% of tumors are malignant– part of the MEN – II syndromes

PHEOCHROMOCYTOMA

• Signs and Symptoms• Paroxysmal

• Diagnostic Clues – SIX “H’s”•Hypertension

•Headache – throbbing (90%)

•Heart palpitations – (73%)

•Hyperhidrosis – (70%)

•Hypermetabolism

•Hyperglycemia

PHEOCHROMOCYTOMA

• Classic Presentation• Predominant Symptoms– H/A, Diaphoresis, Palpitations

•Associated Symptoms– Anxiety and tremor– Pallor and flushing (rare)– Chest and epigastric pain– Painless hematuria

• Timing of episodes– One hour or less – daily to months

PHEOCHROMOCYTOMA

• Diagnosis• Stop all questionable medications• Labs– Plasma Free Metanephrines• Sensitivity/Specificity (99%; 89%)

– Plasma Catecholamines• S/S (85%; 80%)

– 24-hour urine Metanephrines• S/S (76%; 94%)

– 24-hour Urine VMA• S/S (63%; 94%)

PHEOCHROMOCYTOMA

• Diagnosis•Radiology– Adrenal CT scan• S/S (93-100%; 70%)

– Adrenal MRI• S/S (same as CT)

– MIBG scan• Metaiodobenzyl-guanidine• Good for looking for tumors in

unusual places

PHEOCHROMOCYTOMA

• Management•Medical efforts before surgical

•Medical– Alpha Adrenergic Receptor

Antagonists• Phenoxybenzamine• Phentolamine

– Beta blocker AFTER Alpha!• Propanolol

• Surgical

HYPOGLYCEMIA

• Definition: A clinical syndrome of multiple etiologies that results in symptomatic or asymptomatic episodes of low blood glucose levels• Terminology such as “fasting”

or “reactive” (post-prandial) hypoglycemia is not really the best way to classify hypoglycemia

HYPOGLYCEMIA

• Traditional Classifications:• Reactive or Post-Prandial

– Symptoms follow several hours after eating

• Fasting– Symptoms associated with

lack of eating• Secondary

– Symptoms caused by other reasons than those listed above – meds, insulin, illness, disease, etc.

• Factitious– Malicious or intentional

ingestion of oral hypoglycemics or injection of insulin to produce hypoglycemic condition

HYPOGLYCEMIA

•New Thought Classifications:•Healthy Patient Hypoglycemia– consider all likely causes –

meds, medical conditions, drugs, insulinoma, etc.

•Sick or ill Patient Hypoglycemia– Consider all likely causes with

emphasis on the illness-based causes

HYPOGLYCEMIA

•Diagnosis:•Highly clinical in many instances

•Complete patient history

•Blood glucose level during symptomatic episode

HYPOGLYCEMIA

• Symptoms: A wide variety based upon two major categories•Autonomic•Neuroglycopenic

• Symptoms may vary between patients, but they usually are consistent between episodes in any particular patient

HYPOGLYCEMIA

•Autonomic•Diaphoresis

•Tremors

•Flushing

•Anxiety

•Nausea

HYPOGLYCEMIA

•Neuroglycopenic•Dizziness

•Mental confusion

•Fatigue

•Dysarthria

•Headache

•Poor concentration or amnesia

•Seizures

HYPOGLYCEMIA

•Mixed – symptoms that have components of both autonomic and neuroglycopenic •Hunger

•Blurred vision

•Drowsiness

•Weakness

HYPOGLYCEMIA

• Physical Exam•Usually normal by the time the

patient is seen by the medical provider

•May present with minor abnormalities

• Signs are not specific for hypoglycemia in healthy patients

• Signs in ill patients will reflect those signs associated with that illness

HYPOGLYCEMIA

• Etiology•Drugs – ETOH, Quinine, ASA, …

• Insulinomas – hyperinsulinism

•Metabolic conditions like:– Addison’s– Hypopituitarism– Renal Failure– Sepsis or shock– Starvation – anorexia nervosa– Many others – see table 339-1 & H/O

HYPOGLYCEMIA

• Laboratory evaluation•Serum Glucose – most important– normal result during symptomatic

episode effectively rules out hypoglycemia-based condition

•72-hour fast – classic test for dx– < 50mg/dL is termination point

•Beta cell polypeptides– Insulin, C-Peptide, Proinsulin– value varies in relation to glucose

HYPOGLYCEMIA• Laboratory evaluation• Sulfonylureas & Meglitinides– Beta cell polypeptide concentrations are

identical to that noted with an insulinoma rules out factitious etiology if pts are using these meds

• Insulin antibodies– High levels insulin autoimmune d/o– Low level factitious hypoglycemia

• C-Peptide suppression test– C-Peptide formed by conversion of proinsulin

to insulin– Low level exogenous source of insulin– High level insulinoma likely

HYPOGLYCEMIA• Insulinoma

•Diagnosis by:– patient history– insulin levels– US, Spiral CT, MRI of the abdomen –

especially the pancreas

• Treatment:– Surgery is the preferred method– Medical treatment (Diazoxide) may be

used for those patients who are not surgical candidates

HYPOGLYCEMIA•Reactive Hypoglycemia - • Etiology: Prolongation of the effect

of insulin as counter-regulatory mechanism is slow to shut off insulin

•Diagnosis by:– patient history!– insulin levels usually are normal– glucose level during episode – low

• Treatment:– Multiple small meals versus large meals– Mid morning and afternoon snack

HYPOGLYCEMIA• Factitious Hypoglycemia - • Etiology: Usually due to inappropriate

administration of hypoglycemic meds or insulin•Diagnosis by:– patient history!– insulin level during episode High – C-Peptide level during episode Low– glucose level during episode – Low– Sulfonylurea & Meglitinide level High,

if present• Treatment:– STOP offending agent!– Psych eval if deliberate covert use

CONCLUSION Defined Pheochromocytoma

Described the Signs and Symptoms of Pheochromocytoma

Discussed the Work-up and Treatment of Pheochromocytoma

CONCLUSION Defined Hypoglycemia Discussed the Clinical Signs and

Symptoms of Hypoglycemia Discussed the Work-up and

Treatment of Hypoglycemia Discussed Reactive (Post-

prandial) Hypoglycemia Compared true Hypoglycemia to

Factitious Hypoglycemia