Hémorragie intracrânienne et phéochromocytome

Sequence variations in the von Hippel-Lindau tumor suppressor gene in patients with intracranial aneurysms

BACKGROUND

The rupture of intracranial aneurysms leads to subarachnoid hemorrhage, which is often associated with poor outcome. Preventive treatment of unruptured intracranial aneurysms is possible and recommended. However, the lack of candidate genes precludes identifying patients at risk by genetic analyses. We observed intracranial aneurysms in 2 patients with von Hippel-Lindau (VHL) disease and the known disease-causing mutation c.292T > C (p.Tyr98His) in the VHL tumor suppressor gene. This study investigates whether the VHL gene is a possible candidate gene for aneurysm formation.

METHODS

Patients with intracranial aneurysms admitted to our department between 2006 and 2009 were enrolled. The peripheral leukocyte DNA of 200 patients was investigated for sequence variations in the VHL gene using denaturing high performance liquid chromatography. Peripheral leukocyte DNA of 100 randomly sampled probands was investigated as a control group. The allelic frequencies of sequence variations between both groups were compared using the Fisher exact test.

RESULTS

Fourteen of 200 patients with intracranial aneurysms had sequence variations at 6 different loci in the VHL gene. In contrast, no sequence variations were identified in 100 probands in the control group (P = 0.0062). However, none of the single-sequence variations had a statistically significant difference in the allelic frequencies compared to the control group.

CONCLUSIONS

There is accumulating evidence for a genetic basis of aneurysm development. Our investigations lead to the conclusion that the VHL gene is potentially involved in the formation of intracranial aneurysms in a subset of patients. Additional candidate genes need to be identified in order to develop sensitive genetic screening for at-risk patients.

Multiple catecholamine-secreting paragangliomas: diagnosis after hemorrhagic stroke in a young woman

OBJECTIVE

To describe a case of multiple catecholamine-secreting paragangliomas, with a hemorrhagic stroke as the main clinical manifestation.

METHODS

We present a case report with clinical, laboratory, histologic, and genetic details.

RESULTS

A 23-year-old woman with a history of hypertension treated with orally administered medications presented to our emergency department because of sudden onset of hemiplegia of the left side of the body. A computed tomographic scan of the brain showed a right frontoparietal hematoma, and her blood pressure was 185/115 mm Hg. She was admitted to the Department of Neurosurgery, and an external drain was inserted to evacuate the hematoma. She was then referred to the Department of Clinical Sciences, where a search for possible secondary causes of hypertension was undertaken. Substantially elevated urinary levels of vanillylmandelic acid and metanephrines were found, and a pheochromocytoma was suspected. Abdominal computed tomographic scans revealed a large retroperitoneal mass (3.6 by 4 cm) and similar smaller lesions in the right adrenal gland, between the aorta and the vena cava, and in the left paraaortic area. Iodine I 123 metaiodobenzylguanidine scintigraphy showed high uptake in those same areas, consistent with the diagnosis of multiple catecholamine-secreting paragangliomas. After adequate control of the patient's hypertension was achieved with an alpha1-adrenergic receptor blocker, a Ca2+ antagonist, and a beta-adrenergic blocking agent, the tumors were excised in the Department of Surgery. The histopathologic findings confirmed the diagnosis of multiple paragangliomas. The genetic analysis demonstrated an exon 4 mutation in codon 109 (CAA>TAA, Gln>Stop) of the SDHD gene.

CONCLUSION

Although cerebral hemorrhage is an unusual complication of pheochromocytomas or paragangliomas, early recognition of the characteristic symptoms of headache, palpitations, and diaphoresis in a patient with hypertension and prompt appropriate intervention can minimize the morbidity associated with such tumors and prevent a potentially fatal outcome.