Malignant Paraganglioma without Hypertension on Antipsychotic Medication for Schizophrenia

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 37-82-Pheochromocytoma & Paraganglioma
Clinical
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-80
Masayasu Iwabuchi*
Seirei Mikatahara Hosp, Hamamatsu, Japan
Background: Malignant paraganglioma is rare, deceptive and deadly. Chromaffin paragangliomas are extra-adrenal pheochromocytomas that arise from sympathetic ganglia. Hypertension is present in 90% of patients in whom a pheochromocytoma is diagnosed. Hypertension of malignant pheochromocytoma and paraganglioma leads to potentially lethal complications.  Hypertension due to excess of norepinephrine is mainly caused by the contraction of smooth muscle of peripheral blood vessels. Associated with vascular smooth muscle are a large number of alpha1 receptors relative to beta2 receptors. Norepinephrine in physiologically relevant concentrations has little affinity for beta2 receptors. Therefore, norepinephrine will stimulate only alpha1 receptors producing an increase in peripheral vascular resistance. Alpha-adrenergic blockade should be considered to control blood pressure and prevent a hypertensive crisis of malignant paraganglioma.

Clinical case: A 58‐year schizophrenic woman with malignant paraganglioma refused chemotherapy because of pregnancy delusion. CT, PET, MIBG and bone scan indicated metastases to chest wall, lumbar vertebrae and liver confirming the diagnosis of malignant paraganglioma in 2007. Elevated plasma norepinephrine secretion (18220 pg/mL, normal range: 100-450 pg/mL) and elevated 24hr urinary norepinephrine secretion (3789 microgram/day, normal range: 26-121 microgram/day) were observed. On the other hand, her plasma epinephrine and 24hr urinary epinephrine secretion were normal. Her blood pressure has been normal for more than 6 years. Her 24-hour ambulatory blood pressure monitoring (ABPM) and pulse wave velocity (PWV) were normal. There was no need of alpha-adrenergic blockade with antihypertensive drug for her. She has continued to take olanzapine as antipsychotics for schizophrenia.

Clinical Lesson and Conclusion: This is the first case demonstrating the possible role of alpha-adrenergic blockade of antipsychotic drug for malignant paraganglioma. Olanzapine has a high affinity for dopamine, serotonin, histamine, cholinergic muscarinic and alpha-adrenergic receptors. Antipsychotics with a high affinity for alpha-adrenergic receptors have a potential to prevent hypertensive complications of malignant paraganglioma.

Nothing to Disclose: MI

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