Risk Analysis and Management of Third Ventricular Colloid Cysts.

OBJECTIVE: Colloid cysts (CCs) are histologically benign lesions that carry the risk of causing obstructive hydrocephalus. The indication for surgery for symptomatic cysts is unquestioned; however, the management of incidentally detected lesions has remained controversial. We independently evaluated the CC risk score (CCRS) as a useful risk stratification scheme. METHODS: The demographics, imaging characteristics, and clinical presentations of 103 patients with CC during a 10-year period were correlated with symptoms and the occurrence of hydrocephalus. The discriminate capacity of the CCRS was quantified and a decision algorithm formulated. RESULTS: The correlates of symptoms included age <65 years, diameter ≥7 mm, anterior location, hyperintensity on T2-weighted fluid-attenuated inversion recovery (FLAIR) and/or T2-weighted images, and headache at presentation without an alternative explanation. On multivariate analysis, age <65 years, diameter ≥7 mm, and headache at presentation predicted for symptomatic cysts. The CCRS was highly effective at identifying symptomatic patients and those with obstructive hydrocephalus. All patients with cyst growth and symptomatic progression had had an initial CCRS of ≥3 plus hyperintensity (preexisting or developing) on T2-weighted FLAIR images. CONCLUSIONS: The CCRS performed exceptionally well in distinguishing the highest risk patients. Closer follow-up is recommended for younger asymptomatic patients with cysts near the foramen of Monro. Hyperintensity on T2-weighted FLAIR images might indicate greater growth potential for small lesions.

Correction.

[This corrects the article on p. 8 in vol. 10.].

Angioleiomyoma of the falx.

A 43-year-old man arrived at the emergency department following a syncopal episode. Computed tomography and magnetic resonance images demonstrated a small interhemispheric, anterior parafalcine mass that mimicked a meningioma. Surgical excision and subsequent pathologic evaluation revealed an angioleiomyoma and the patient recovered without incident. Angioleiomyomas are classified as benign smooth muscle tumors and are classically seen in adult females arising in the soft tissues of the lower extremities. Although rare, these masses have been described in various intracranial locations, usually extra-axially. A comprehensive review of the literature and discussion are provided, emphasizing histopathologic and imaging features of this uncommon intracranial neoplasm.

MR spectroscopy in the diagnosis of cerebral amyloid angiopathy presenting as a brain tumor.

We present two cases of focal, tumefactive, masslike lesions of diffuse cerebral amyloid angiopathy (CAA) that presented as areas of increased signal intensity on long TR sequences without contrast enhancement or restricted diffusion. MR spectroscopy revealed normal metabolite ratios and unremarkable spectra. Pathologic tissue showed CAA and CAA with angitis of the CNS. Tumefactive CAA is a rare condition, and we describe its characteristics at MR spectroscopy and diffusion-weighted imaging.