Introduction: A case series regarding the clinical presentation, imaging and pathology of patients with calcified pseudoneoplasms of the neuroaxis (CAPNON)
Methods: Analysis of pathology database for cases of CAPNON from 2013 to 2014. Patient data collected include age, gender and race. Clinical details recorded include presenting history, radiology findings, intraoperative findings and histology.
Results: Four cases were found. All four patients were of Maori descent. Three patients had generalised tonic-clonic seizures whilst one other patient presented with ataxia and headaches. A heavily calcified mass was seen imaging of the head. Macroscopic surgical excision of the lesion was successful in all cases. Histological findings of note were: densely calcified nodules, radially arranged spindle cells and epithelioid cells, central areas of metaplastic bone formation and fibrovascular stroma. No recurrence was seen in all cases during follow up at the 3 and 12 month mark.
Conclusions: CAPNONs are rare tumours of the central nervous system that may mimic low grade tumours radiologically. Histologically these lesions may appear similar to WHO Grade I pilocytic astrocytomas. Given the benign nature of these tumours the decision for surgical excision should be considered carefully given the risks involved.
Patient Care: Minimise the need for surgery in cases of benign tumours
Learning Objectives: CAPNONs are very difficult to diagnose radiologically. Biopsies may be equally challenging given the heavy calcification often seen in these tumours. Prudent observation may be a superior alternative to early surgical intervention.