Resident Physician Northwestern Neurosurgery Chicago, Illinois, United States
Introduction: Calcified pseudoneoplasms of the neuraxis (CAPNON) are rare non-neoplastic lesions that occur in the brain or less frequently in the spine. Spinal CAPNON, although considered benign, can cause neurologic symptoms mostly related to mass effect. Our objective was to synthesize available evidence of presentation, diagnosis and management of spinal CAPNON.
Methods: A systematic review according to the PRISMA guidelines was conducted by searching the PubMed/Medline and Cochrane databases.
Results: A total of 14 studies comprising 26 patients (median age 58yo, female 65.4%) and 28 histologically confirmed cases were included. The most common clinical presentation was some type of pain (n=24/26; 92.3%) while 9/26 (34.6%) of patients presented with lower extremity weakness and/or myelopathy. Only one lesion was found incidentally. CT imaging showed calcifications in all lesions with available data. The majority of lesions were hypointense on T1 (88.2%) and T2 (82.4%) and demonstrated some type of enhancement on contrasted imaging (62.5%). Most of the spinal CAPNONs with available data were intradural extramedullary (n=11/18; 61.1%); the rest of the lesions extradural (n=7/18; 38.9%). The lesions were located in the lumbar (35.7%), thoracic (32.1%) and cervical spine (28.6%). Median maximum diameter was 1.5 cm (range 0.3-6.5cm). Most common histopathologic findings were calcifications (100%), amorphous granular material (96.4%) and peripheral spindle or epitheliod cells (82.1%). The majority of the lesions were approached dorsally through a laminectomy for tumor resection (n=27/28; 96.4%). Gross total resection was achieved in 20/27 patients (72.4%). Two patients underwent biopsy first and one was managed conservatively while the other underwent subsequent resection at a later time. Post-operatively none of the lesions showed any growth during the median follow-up of 31.5 months.
Conclusion : Spinal CAPNON commonly presents with pain, lower extremity weakness and/or myelopathy. Calcification is the most prevalent finding on imaging and histopathology. The majority of patients undergo laminectomies for resection of tumor and tissue diagnosis; none of the lesions progressed during the follow-up.
How to Improve Patient Care: This is the first systematic literature review of spinal CAPNON reporting the natural history of the disease as well as surgical management and outcomes.
