Child Neurology: Pheochromocytoma Unveiled by Reversible Cerebral Vasoconstriction Syndrome in a Child With Neurofibromatosis Type 1

(A) Contrast-enhanced CT angiogram performed at presentation to evaluate thunderclap headache shows abnormal irregular narrowing (arrowheads) of multiple segments of the bilateral intracranial arteries including left anterior cerebral artery, bilateral middle cerebral artery, and supraclinoid right internal carotid artery. (B) A 3D fat-suppressed postcontrast T1 sampling perfection with application optimized contrast using different flip-angle evolutions (SPACE) MRI obtained the following day shows no substantial vessel wall thickening or enhancement, accounting for minor subtraction artifact (vessel lumina are black on this subtraction image). The MRI was repeated 3 months after presentation, and (C) time-of-flight magnetic resonance angiography showed substantial overall improvement of the previously identified multivessel irregular narrowing. Negligible luminal irregularity along the distal left M1 segment persisted (*). Once again, no vessel wall thickening or enhancement was seen (D), confirming the absence of any large vessel vasculopathy. The right suprarenal mass identified during the initial evaluation was found to be intensely I-123 MIBG-avid (E), compatible with pheochromocytoma, later confirmed via pathology. All CNS images are coronal views at the same position through the sella turcica and circle of Willis. Ca = carotid artery; P = pituitary gland; S = suprarenal mass; V = lateral ventricle.