Calcifying Pseudoneoplasms of the Neuraxis: CT, MR Imaging, and Histologic Features

• Published in: American journal of neuroradiology : AJNR Vol. 30; no. 6; pp. 1256 - 1260
• Main Authors: Aiken, A.H, Akgun, H, Tihan, T, Barbaro, N, Glastonbury, C
• Format: Journal Article
• Language: English
• Published: Oak Brook, IL Am Soc Neuroradiology 01.06.2009; American Society of Neuroradiology
• Subjects: Biological and medical sciences; Brain; Calcinosis - complications; Calcinosis - diagnosis; Central Nervous System Diseases - diagnosis; Female; Fundamental and applied biological sciences. Psychology; Humans; Investigative techniques, diagnostic techniques (general aspects); Magnetic Resonance Imaging - methods; Male; Medical sciences; Nervous system; Perception; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Tomography, X-Ray Computed - methods; Vision; Nervous system diseases; Computerized axial tomography; Radiodiagnosis; Nuclear magnetic resonance imaging
• ISSN: 0195-6108; 1936-959X
• DOI: 10.3174/ajnr.A1505

Non-neoplastic, calcified, fibro-osseous lesions known as "calcifying pseudoneoplasms of the neuraxis" (CAPNON) are rare and can occur anywhere within the neuraxis. The radiologic and histopathologic characteristics of this unusual entity are not well understood. We present the largest series reviewing the MR imaging features of CAPNON. The MR and CT imaging features in 4 patients with a pathologic diagnosis of "calcifying pseudoneoplasms of the neuraxis" were retrospectively reviewed. A neuropathologist also analyzed the histopathologic features for typical and atypical patterns. Imaging features were strikingly similar for all 4 patients. All lesions appeared T1 and T2 hypointense without vasogenic edema. All tumors had dense calcification, and 3 tumors showed minimal linear internal or rim enhancement on MR imaging. CAPNON may mimic more common vascular malformations or neoplasms and are often not considered in the differential diagnosis of calcified lesions. CAPNON should be included in the differential diagnosis of a calcified mass with marked T1 and T2 hypointensity and limited to no enhancement. Careful CT and MR imaging evaluation can suggest this entity, and this preoperative recognition may help subsequent management decisions.