A 40‐year‐old G9P8 Yemeni woman with hypertension and diabetes mellitus at 32 weeks of pregnancy presented to the emergency room with 11 days of left otalgia and facial droop. She also had intermittent tinnitus and gradual hearing loss over the last several years. On presentation she was hypertensive at 150/89 and otherwise had stable vital signs. On exam she had grossly diminished hearing on the left and a red mass medial to the left tympanic membrane (TM). She also had CN VII paresis. Her initial complete blood count and comprehensive metabolic panel were normal. A temporal bone CT showed a large mass centered within the left caroticojugular foramen, and MRI of the brain showed intense postcontrast enhancement of the same lesion. Her hospitalization was complicated by severe preeclampsia, for which she required a cesarean section. Postoperatively she developed severe hypoxia. Her PECT was negative but showed a well‐circumscribed mediastinal mass. During the hospitalization, her serum‐free normetanephrine was found to be elevated at 10.6 nmol/L (normal < 0.9), whereas her metanephrine was normal. Meanwhile, her 24‐hour urine collection for norepinephrine was also elevated, at 3861 μg (normal, 50–800 μg), whereas her epinephrine was normal. Finally her MIBG scan was positive for both left skull base and mediastinal mass, which confirmed 2 functional paragangliomas (PGs). She was started on phenoxybenzamine and propanolol. Her genetic testing came back positive for heterozygous succinate dehydrogenase (SDH) C. Subsequently she declined resection of her tumors.
The prevalence and incidence of PG are unknown. The Mayo Clinic reported the largest series of 236 cases between 1978 and 1998. PGs are inherited in 10%–50% of cases and associated with SDH (B, C, or D) mutations. Malignant and multiple PGs are more common in inherited forms. In general PG is slow growing (1 mm annually) and fewer than 10% become malignant. Overall, 31% of PGs and 1%–3% of head and neck cases are functional. They arise from widely dispersed neural crest cells that can be found in the head, neck, chest, and abdomen. They can secrete neuropeptides and catacholamines, which cause hypertension, palpitation, and diaphoresis. Other clinical presentations include headache, dysphagia, hearing loss, tinnitus, a reddish bulge behind TM, cranial nerve palsies, or neck mass. PGs can be evaluated by multiple imaging modalities including CT, MRI, angiography, and NM studies. Biopsy is relatively contraindicated and usually unnecessary for diagnosis of PG. Because PGs do not secrete epinephrine, an elevated epinephrine in serum or urine suggests a pheochromocytoma. Surgery is usually the treatment of choice when significant tumor growth or symptoms exist. Radiotherapy is usually used for poor surgical candidates. Chemotherapy is predominantly used for metastatic PGs.
PG is a very rare cause of hypertension thyat counts for fewer than 0.5% of all cases. Hospitalists need to be aware of its presentation, diagnosis, and treatment.
B. Xue ‐ none; S. Smith ‐ none
To cite this abstract:Xue B, Smith S. It's Not a Horse or Even a Zebra! a Rare Cause of a Common Condition. Abstract published at Hospital Medicine 2011, May 10-13, Dallas, Texas. Abstract 433. Journal of Hospital Medicine. 2011; 6 (suppl 2). https://www.shmabstracts.com/abstract/its-not-a-horse-or-even-a-zebra-a-rare-cause-of-a-common-condition/. Accessed June 17, 2019.