Imaging features of intracranial psammomatous meningioma

Purpose: This study was conducted to describe the imaging features of intracranial psammomatous meningioma (IPM).

Materials and methods: Twenty-three patients with a histopathological diagnosis of IPM between January 2007 and August 2016 were retrospectively reviewed. Twenty-two patients underwent contrast-enhanced MRI scanning, and 16 underwent non-enhanced CT.

Results: A total of 23 adult patients (3 men, 20 women; mean age, 55.3±7.0 years) with 30 IPMs, including 3 patients with multiple IPMs, were recruited. Twenty tumours (66.7%) were located at the cerebral convexity. The mean size of the lesions was 2.42±0.92cm (range, 1.2-4.8cm). All tumours had a regular shape. On CT scans, 13 masses (13/22) were totally replaced with calcifications, and calcifications were observed in 21 cases (21/22) with higher density. There were 22 cases (22/30) of IPMs presenting adjacent hyperostosis, while 8 cases (8/30) presented no skull changes that were not close to the skull. Nearly half of the cases (14/29) showed mixed hypo- and hyperintensity on T2-weighted images and DWI. PTBE was present in 8 tumours and absent in the other 22, among which only 4 tumours were accompanied by severe oedema.

Conclusions: These radiological findings may facilitate correct diagnosis for IPMs and thus presurgical planning, prognosis evaluation and treatment of meningiomas.