Pheochromocytoma

Pheochromocytoma

I – definition:

• Pheochromocytoma is an adrenal tumor that develops at the expense of chromaffin cells and secretes catecholamines.
•  It causes persistent or paroxysmal hypertension. 
• Diagnosis is based on plasma or urine measurement of methoxylated derivatives of catecholamines. Imaging tests, including CT or MRI, can locate tumors.
•  Treatment is based on surgery, when the tumor is resectable. 
• Drug treatment of hypertension is based on alpha-blockade, usually combined with beta-blockade.
• The secreted catecholamines include norepinephrine, adrenaline, dopamine, and dopa in varying proportions. 
• Approximately 90% of pheochromocytomas are located in the adrenal medulla 
• Adrenal medullary pheochromocytomas are observed in men and women, they are bilateral in 10% of cases (20% in children) and malignant in < 10% of cases. 
• Among extra-adrenal tumors, known as paragangliomas, 30% are malignant.
•  Although pheochromocytomas occur at all ages, the peak incidence is between 20 and 50 years of age. Nearly 50% of cases are thought to be caused by germline genetic mutations.

II- Symptomatology:

• The main sign is hypertension, which is paroxysmal in 45% of patients. 
• About 1/1000 of hypertensive people have a pheochromocytoma. Common symptoms include: 
• Tachycardia
• Sweating
• Orthostatic hypotension
• Tachypnea 
• Cold and clammy skin
• Severe headaches
• Angor
• Palpitations
• Nausea and vomiting
• Epigastric pain
• Visual disturbances
• Dyspnea
• Paresthesias
• Constipation
• A sense of impending doom
• Paroxysmal crises may be triggered by palpation of the tumor, changes in position, abdominal compression or massage, induction of anesthesia, emotional shock, prescription of a beta-blocker (which paradoxically increases blood pressure by blocking beta-receptor-mediated vasodilation), and rarely, urination (if the tumor is in the bladder).
•  In elderly patients, severe weight loss with persistent hypertension is suggestive of pheochromocytoma.

III- Diagnosis:

• Plasma or urinary metanephrines and normetanephrines
• Imaging of the thorax and abdomen (CT or MRI) in case of elevation of methoxylated derivatives of catecholamines
• Possibly nuclear imaging by I-123 MIBG (metaiodobenzylguanidine) or PET with Gallium-68 dotatate 

IV- Treatment:

• Control of hypertension is based on the combination of alpha- and then beta-blockers 
• Surgical removal of the tumor with close perioperative monitoring of blood pressure and volume status
• The treatment of choice is surgery. 

V- Conduct to be adopted in odontostomatology:

• In the chair, one may first fear the occurrence of an acute hypertensive crisis leading to a hypertensive emergency.
•  A hypertensive surge leading to a feeling of discomfort (epistaxis, dizziness, tinnitus, headaches) is also not desirable for anyone. 
• In oral surgery there is also a risk of hemorrhage, on a simple hypertensive surge or on a less punctual but very present increase in blood pressure.
•  First, the medical questionnaire will screen hypertensive patients and their treatment.

 Contact with the treating physician may be necessary to ensure that the hypertension and any other associated pathologies are well balanced.

• No surgical procedure should a priori be undertaken on unstabilized hypertension.
• Every hypertensive patient, even a well-balanced one, should have their blood pressure checked before any surgical procedure: there are very reliable wrist blood pressure monitors available at any pharmacy at low cost. 
• To limit anxiety and make sessions more comfortable, it is advisable, particularly in these patients, to prefer short sessions, scheduled in the morning, and to prescribe sedative premedication. 

Pheochromocytoma

VI- Respect for drug interactions:

1. BETA BLOCKERS They interact with:

 – AIS which cause long-term hydrosodic retention and reduce the hypotensive effect;

 – NSAIDs which reduce the hypotensive effect by inhibiting vasodilatory prostaglandins; 

– floctafenine (analgesic): absolute contraindication; 

– intestinal topicals which reduce the digestive absorption of beta-blockers. 

2.  DIURETICS 

They interact with:

 – AIS which cause long-term hydrosodic retention and reduce the hypotensive effect 

3. CENTRAL ANTIHYPERTENSIVE DRUGS Interaction with NSAIDs which reduce the hypotensive effect.

 Due to an increased risk of neurosedation, contraindication to the concomitant prescription of other CNS depressants (sedative premedications: hydroxyzine, benzodiazepines). 

4. CALCIUM INHIBITORS They interact with: 

– AIS which reduce the hypotensive effect;

 – itraconazole and ketoconazole (antifungals) which increase the adverse effects of calcium channel blockers: there is competition at the level of hepatic metabolism which leads to a risk of edema (except for verapamil and diltiazem). 

5. ANGIOTENSIN CONVERTING enzyme (ACE) INHIBITORS ANGIOTENSIN AR II RECEPTOR ANTAGONISTS (ARAII) They interact with:

– AIS which reduce the hypotensive effect;

 – NSAIDs which reduce the hypotensive effect and can cause acute renal failure in predisposed subjects (by reducing glomerular filtration by inhibiting the synthesis of vasodilatory PGs)

VII- Oral manifestations linked to the adverse effects of hypotensive treatments

1. HYPOSIALIA

 It can be caused by certain diuretics, central antihypertensives, alpha-blockers, calcium channel blockers and is reversible when treatment is stopped.

2- GINGIVAL HYPERPLASIA:

• Some calcium channel blockers such as nifedipine can cause the appearance of localized or generalized gingival hyperplasia which appears 2 to 4 months after the start of treatment and gradually disappears within a few months after its discontinuation. 
• The gum is soft and hemorrhagic.
•  The anatomopathological analysis reveals very dense inflammatory infiltrates. 

3-DYSGUEUSIA:

 It is reversible when treatment is stopped and can be caused by certain calcium channel blockers and angiotensin converting enzyme inhibitors. 

It manifests itself by an alteration of taste perception at the level of the lingual papillae.

4-SKIN RASH:

• They can be observed in patients treated with calcium channel blockers, angiotensin converting enzyme inhibitors, alpha-blockers. 

VIII- Precautions in the context of anesthesia

• The use of vasoconstrictors in oral surgery is of considerable benefit:

 – they help limit per-operative bleeding;

 – they increase the duration of action of the anesthesia;

 – they allow the injection of lower doses, therefore reducing systemic toxicity.

 They significantly improve the effectiveness of anesthesia. 

Pheochromocytoma

IX- CONSEQUENCES OF THE USE OF ADRENALINE ANESTHETICS

• Adrenaline acts on certain adrenergic receptors and causes an increase in blood pressure by stimulating the force and speed of the heartbeat.
•  The potential risk in the hypertensive patient is therefore to trigger a hypertensive surge by a rapid and massive injection.
•  A 1/100,000 adrenaline cartridge contains 17 mg of adrenaline, which corresponds to the endogenous secretion per minute of the relaxed patient, but which is negligible compared to the endogenous secretion of the anxious patient. 

1. ADRENALINE / BETA-BLOCKERS INTERACTION

There is competition between the two molecules because they act on the same beta-adrenergic receptors; the antihypertensive effect of the beta-blocker may therefore be reduced. Consequently, we will follow the recommendations cited above. 

2. LIDOCAINE (XYLOCAINE) / BETA-BLOCKER INTERACTION

A decrease in the hepatic metabolism of lidocaine has been described during concomitant treatment with certain beta-blockers (propranolol, metoprolol and nadolol).

 The plasma level of lidocaine therefore increases, which increases the risk of overdose, with neurological and cardiac toxicity.

 We will therefore avoid xylocaine, which can be advantageously replaced by other molecules such as articaine. 

3. LIDOCAINE (XYLOCAINE) / BETA-BLOCKER INTERACTION

A decrease in the hepatic metabolism of lidocaine has been described during concomitant treatment with certain beta-blockers (propranolol, metoprolol and nadolol).

The plasma level of lidocaine therefore increases, which increases the risk of overdose, with neurological and cardiac toxicity.

 We will therefore avoid xylocaine, which can be advantageously replaced by other molecules such as articaine. 

4. INTERACTION WITH GENERAL ANESTHETICS

General anesthetics potentiate antihypertensive drugs and may cause severe hypotension; therefore, whenever possible, local anesthesia should be preferred to general anesthesia in these patients. 

Hyperparathyroidism​ 

1. Definition

abnormally high production of parathyroid hormone (PTH) by the parathyroid glands. 

This can be primary or secondary. The increase in PTH leads to an increase in plasma calcium levels.

• Primary hyperparathyroidism (HPT1), asymptomatic in the majority of cases, is characterized by hypercalcemia caused by autonomous hypersecretion of parathyroid hormone, most often a parathyroid adenoma. 
• The diagnosis of asymptomatic HPT1 is therefore biological in view of the absence of symptoms leading to the diagnosis, which may be linked either to hypercalcemia, or to renal lithiasis or to damage to the osteoarticular system (chondrocalcinosis, bone pain secondary to a brown tumor or fracture)

Pheochromocytoma

Maxillo-buccodental manifestations of hyperparathyroidism

Pheochromocytoma

• Other manifestations are related to genetic factors such as fibrous tumors of the jaw in connection with mutations in the gene coding for parafibromin. 

2. Evolution

Renal damage: Renal complications (nephrolithiasis, nephrocalcinosis)  

Bone involvement and fracture risk: HPT1 decreases bone densitometry at cortical sites such as the distal radius, although fracture risk at the hip (mixed trabecular and cortical bone) and vertebral levels is also described. 

3. Treatment : 

• Surgical treatment: 

A parathyroidectomy 

• Drug treatment: 

Surgical contraindications, or after surgery failure.

Bisphosphonates: Alendronate (Fosamax) is the most studied bisphosphonate in HPT1.

Pheochromocytoma

Hypoparathyroidism

1. Definition

Hypoparathyroidism is the set of manifestations (clinical and biological) occurring when the secretion of PTH by the parathyroid glands is insufficient to maintain normal concentrations of extracellular (ionized) calcium.

The clinical signs are mainly those of hypocalcemia and the diagnosis is then suggested by the biological association of hypocalcemia, hyperphosphatemia, and an inappropriate blood concentration of PTH (zero or low or within the normal range). 

• Hypoparathyroidism responds to three main nosological frameworks: 
•  Acquired hypoparathyroidism: 
•  post-surgical: in adults, this is by far the most common cause of hypoparathyroidism; it can occur after any neck surgery but mainly following two types of intervention: after parathyroidectomy or after thyroid surgery (3-4% of definitive hypoparathyroidism) 
•  post-radiation therapy of the neck
•  by infiltration of the parathyroid glands (as in Wilson’s disease, primary or secondary hemochromatosis, amyloidosis, thalassemia major or tuberculosis) 
•  autoimmune due to antibodies directed against CaSR 
• Congenital hypoparathyroidism. 

2. Symptomatology

Acute onset hypocalcemia: infant malaise, generalized convulsions, laryngospasm, cardiac rhythm disorders with clinical repercussions (ventricular tachycardia or even torsade de pointes), ventricular failure. 

3. Dental anomalies:

Dental abnormalities can be found in chronic hypoparathyroidism, if it is present during the period of tooth formation: enamel hypoplasia (failure of tooth enamel formation), increased susceptibility to dental caries. 

4. Complications of hypocalcemia:

1. Cataract

2. Various calcifications Hypoparathyroidism, although the mechanism is not clearly elucidated, is classically complicated by calcifications in certain target organs (brain, soft tissue such as subcutaneous tissue, muscles, heart and heart vessels and valves). 

3. Renal complications Renal complications of hypoparathyroidism are kidney stones, nephrocalcinosis and renal failure. 

Pheochromocytoma

  Sensitive teeth react to hot, cold or sweet.
Sensitive teeth react to hot, cold or sweet.
Ceramic crowns perfectly imitate the appearance of natural teeth.
Regular dental care reduces the risk of serious problems.
Impacted teeth can cause pain and require intervention.
Antiseptic mouthwashes help reduce plaque.
Fractured teeth can be repaired with modern techniques.
A balanced diet promotes healthy teeth and gums.
 

Pheochromocytoma