Endocrine Abstracts

JOINT3525

Introduction: The most common symptom of hypertension (HT) in childhood is headache, frequently accompanied by tachycardia. In infants and toddlers, it is predominantly caused by cardiac and renal pathologies, whereas essential HT is more common in adolescents. Among endocrinological disorders, pheochromocytoma is the leading cause of episodic HT. This case report highlights a rare condition that warrants consideration in the differential diagnosis of pheochromocytoma.

Case: A 17-year-old female presented with headache, palpitations and presyncope. Her systolic blood pressure was 170/100 mm Hg and pulse rate 135/minute. She responded to amlodipine but experienced recurrence during follow-up. Renal ultrasonography, renal doppler USG, plasma renin activity, angiotensin and aldosterone levels were normal. Investigating pheochromocytoma, urinary 3-Methoxytyramine levels were found to be elevated in two measurements, 174 µg/g and 533 µg/g. MIBG scintigraphy revealed subcentimetric lymph node involvement in the right paraaortic area. Clinical monitoring was deemed adequate, as the area was unsuitable for biopsy and not fully consistent with clinical findings. During follow-up, as hypertension and tachycardia persisted, the patient underwent PET-CT with gadolinium, showing no uptake. Thoracic and abdominal angiography were normal, but conventional angiography revealed contour irregularities and occlusions in distal branches of bilateral renal arteries, potentially indicating vasculitis. However, vasculitis was not considered due to lack of constitutional or cutaneous findings, no pulse and blood pressure discrepancy between extremities, and negative acute phase reactants and autoantibodies. Ramipril and metoprolol were respectively added to her treatment to control blood pressure. As hypertensive episodes continued and no benefit was observed, medications were gradually tapered. Urinary porphyria metabolite levels were analyzed, with porphobilinogen, delta-aminolevulinic acid and coproporphyrinogen III levels high in both attacks and attack-free periods. Intravenous dextrose infusion during a hypertensive episode reduced blood pressure and improved symptoms. A peripheral blood sample was obtained for genetic analysis to screen for porphyria-associated variations, with results pending.

Conclusion: While porphyria is characterized by cutaneous lesions, anemia, hepatic impairment, and neuropathies, some patients may present solely with tachycardia, HT, and presyncope episodes due to autonomic dysfunction. Although this clinical presentation resembles pheochromocytoma, paradoxical responses may be observed due to the precipitating effect of calcium channel blockers and angiotensin converting enzyme inhibitors on porphyria attacks. Intravenous administration of hemin or glucose during an acute episode provides significant clinical improvement. Porphyria should be considered in the differential diagnosis when encountering episodic hypertension, tachycardia, emesis, and presyncope.