Severe Posterior Reversible Encephalopathy in Pheochromocytoma: Importance of Susceptibility-Weighted MRI
A 13-year-old girl was presented with flushing and swelling on her hands and feet, sweating and critical headache for one year. On her medical history; she had previously been admitted for similar complaints and underwent surgery. Right adrenalectomy was made seven years ago and pathology result was pheochromocytoma. She had been discharged with a cure and a recommendation of interval follow-ups. But, the patient did not attend any follow-up visits nor receive any treatments over the last seven years. She started to complain of similar symptoms again since last year. On physical examination; she had cyanosis and edema on both hands and feet. The patient's blood pressure was 215/165 mm Hg, and her pulse rate was 137 beats per minute. Biochemical and radiological examinations were performed to determine recurrent pheochromocytoma. Urinary and plasma catecholamine levels were high. Urinary normetanephrine level was 30084 µg/24 h (reference values are 63-402 µg/24 h), urinary metanephrine level was 1452 µg/24 h (reference values are 32-167 µg/24 h), plasma noradrenalin level was 17540 pg/mL (reference values are 0-400 pg/mL). Contrast enhanced abdominal MRI was performed with a large mass within the left adrenal gland, measuring 65 × 50 mm in size. It was hypointense on T1-weighted and heterogeneous hyperintense on T2-weighted image with intense enhancement on post-contrast images (), suggesting residue or recurrence of the adrenal pheochromocytoma. Cranial MRI was performed because of serious headaches. T2-weighted and fluid attenuated inversion recovery (FLAIR) images showed abnormal hyperintense signals on bilateral caudate, lentiform nuclei, dentate nuclei and periventricular and deep white matter (). Furthermore, there were two hematomas; a chronic hematoma with peripheral hemosiderin rim on the right external capsule measuring 3 × 1 cm in size and a subacute hematoma on the right globus pallidus measuring 1 cm in diameter (). There was increased diffusion in the lesions consistent with the vasogenic edema. These findings were consistent with severe PRES for the involvement of periventricular and deep white matter and deep gray matter as well as parenchymal hematomas.\nOn the tenth day of anti-hypertensive therapy, we obtained follow-up cranial MRI with additional SWI sequence. There was remarkable regression of vasogenic edema with near completed resolution of T2 high signal intensities on periventricular and deep white matter, and complete loss of edema on caudate, lentiform, and dentate nuclei (). On SWI, many millimetric foci of hypointensity suggesting micro hemorrhages were observed on bilateral basal ganglia, periventricular white matter and brain stem (). These microhemorrhagic foci were not detectable on conventional MRI. Reversible high signal intensities supported that this condition was PRES secondary to hypertension. SWI sequence revealed many micro and macro hemorrhagic foci of hypertensive encephalopathy as a complication of untreated chronic hypertension.