Pediatric cryptic vascular malformations: presentation, diagnosis and treatment.

Since the advent of magnetic resonance (MR) imaging, angiographically occult or 'cryptic' vascular malformations (CVMs) have been detected with increasing frequency in the pediatric population. The natural history of these lesions is uncertain and treatment remains controversial. We respectively reviewed the presentation, radiology, treatment and outcome of 37 pediatric patients with CVMs seen at our institution between 1982 and 1992. MR imaging was diagnostic in all patients studied. Angiography was negative in 20 of 21 patients studied, while 1 teenage girl was found to have a venous malformation. Total surgical excision was the treatment goal in all patients presenting with symptomatic CVMs. There has been no surgical mortality. Perioperative complications occurred in one third of the patients but quickly resolved in most cases. Only 2 patients with multiple CVMs, including brainstem lesions, who presented with progressive neurologic deficits were clearly worse following surgery. Six of seven patients with radiation-induced CVMs have remained asymptomatic with close radiographic follow-up, while 1 patient with a hemorrhage has required surgical evacuation. We conclude that CVMs occur more commonly in the pediatric population than previously assumed. Patients presenting with seizures or hemorrhage should undergo craniotomy with the goal of complete excision. Radiation therapy plays no role in the treatment of these lesions and may actually result in their formation. Careful clinical and radiological follow-up is critical to assess the completeness of surgical removal and to evaluate progression of lesions in patients with multiple or radiation-induced CVMs treated conservatively.