Pheochromocytoma

Pheochromocytoma (PCA)
By Dr. Usama Ragab Youssif
Lecturer of Medicine Zagazig University

Pheochromocytoma and paraganglioma

1. Suprarenal Medulla Usama Ragab Youssif, MD Lecturer of Medicine Zagazig University Email: [email protected] Slideshare : https://www.slideshare.net/dr4spring/ Mobile: [phone]

2. Suprarenal Gland There are two human adrenal glands each weighing only 4 – 5 gm, one at the superior pole of each kidney. The cortex represents 90% of the normal gland and surrounds the medulla . The adrenal medulla secretes catecholamines (CA) : Epinephrine. Norepinephrine. Dopamine

3. Medulla It is sympathetic ganglia which secretes CA .

4. Nomenclature

5. Pheochromocytoma and Ganglioma

6. Pheochromocytoma and Ganglioma (cont.) Sympathetic paraganglia occur as follows: in prevertebral, paravertebral, thoracoabdominal, etc. They are termed extra-adrenal functional paraganglioma ( eFPGL ) . Parasympathetic paraganglia are located close to major arteries and nerves, e.g., carotid body, glomus jugulare , etc. They are termed head and neck paraganglioma (HNPGL) , and only a minority of those shows endocrine activity (~25%).

7. Notes

8. Inherited syndromes of PCA

9. Epidemiology

10. Secretory products

11. Importance of diagnosis

12. Presentation The presence of palpitation , headaches , or sweating in a patient with hypertension should raise the diagnostic query of PCA. General : Sweating and heat intolerance >80%. Pallor or flushing. Feeling of apprehension. Pyrexia

13. Presentation (cont.)

14. Presentation (cont.)

15. Why sometimes there is hypotension

16. Complications CVS : LVF, DCM (reversible), hypertension, arrhythmia Pulmonary : pulmonary edema Metabolic : impaired glucose tolerance, hypercalcemia CNS : hypertensive encephalopathy, target organ damage

17. Factors that may precipitate crisis Straining Exercise Abdominal palpation Surgery Drugs e.g., beta blockers, IV contrast, anesthesia, tricyclic antidepressant, metocloperamide , glucagon

18. Take Care Differential diagnosis Anxiety-panic attacks Hypoglycemia Other causes of hypertension = 2ry hypertension Diencephalic or autonomic epilepsy (attacks of hypertension with increased CA Endocrine causes of excess sweating Thyrotoxicosis Acromegaly Hypoglycemia Pheochromocytoma

19. Workup

20. Who should be screened? Patients with a family history of MEN, VHL, NF1. Patients with paroxysmal symptoms. Young patients with hypertension. Patient developing hypertensive crisis during general anaesthesia /surgery. Patients with unexplained heart failure. Patients with an adrenal incidentaloma.

21. Two Questions

22. What is the lesion

23. 1- 24h urine collection for catecholamines/ metanephrines The sensitivity of urinary VMAs is less than free catecholamines or metadrenalines and influenced by dietary intake and should not be used. Urinary metanephrines are of similar sensitivity but of superior specificity to urinary catecholamines .

24. 2- Plasma metanephrines Plasma metanephrines are the most sensitive test for detection of catecholamine excess and have only slightly lower specificity than urinary metanephrines . If plasma metanephrines are borderline, urinary metanephrines may be used for confirmation. Plasma catecholamines are elevated by renal failure, caffeine, nicotine, exercise, and some drugs.

25. 3- Clonidine Suppression test It lowers the norepinephrine in normal persons but not in patients with PCA. 300 mcg orally → failure of suppression to normal range within 120 and 180 minutes

26. Comparable tests Test Sensitivity % Specificity % Plasma metanephrines 97 92 Urinary metanephrines 85 95 Urinary catecholamines 88 78 Urinary VMA 65 88 Clonidine suppression test 97 MRI 98 70 CT 93 70 MIBG 80 95

27. List of medications and stimulants to avoid before the measurement of plasma and urinary catecholamines and metanephrines Tricyclic antidepressants Beta-blockers: labetalol * and sotalol Acetaminophen Phenoxybenzamine Monoamine oxidase inhibitors Antipsychotics Sympathomimetics: ephedrine, pseudoephedrine , amphetamines, albuterol Stimulants: caffeine , nicotine, theophylline Miscellaneous: levodopa, carbidopa, alcohol, cocaine *Labetalol interferes only with certain assays

28. Where is the lesion

29. Localization

30. Localization (cont.)

31. Algorithm for the tumor localization in patients with biochemically proven pheochromocytoma

32. CT and MRI

33. MIBG

34. What about genetic condition? When to screen? Bilateral tumours. Extra-adrenal tumour, including head and neck. Age of onset (<50 years 45%). Malignancy. MEN II VHL NF1 Serum calcium. Serum calcitonin (phaeochromocytomas precede medullary thyroid carcinoma in 10%). Ophthalmoscopy—retinal angiomas are usually the first manifestation. MRI—posterior fossa and spinal cord. US of kidneys—if not adequately imaged on MRI of adrenals. Clinical examination for café-au-lait spots and cutaneous neuromas.

35. Treatment

36. 1- Medical

37. 1- Medical (cont.)

38. Metyrosine Metyrosine (tyrosine hydroxylase inhibitor) blocks the formation of norepinephrine and epinephrine. It may be used when patients are intolerant of the adrenergic blockers.

39. 2- Surgical Surgical resection is curative ≈ 75%. Need expert anesthetic team: tumour handling → major changes in BP ± arrhythmias. Surgery may be laparoscopic if the tumour is small and apparently benign.

40. Risk factors for haemodynamic instability during surgery include

41. Follow-up

42. Thank you