Fibro-osseous lesions of the central nervous system - Report of-four casesand literature review

Fibro-osseous lesions, also reported as calcifying pseudoneo-plasms of the neural axis, are uncommon lesions of the CNS. We report four additional cas es: two extraaxial and two intraaxial, in patients ages 33, 47, 49, and 59 years at presentation. Fibro-osseous lesions involving the CNS demonstrate variable proportions of fibrous stroma, bone, palisading spindle to epithel ioid to multinucleated cells in association with a highly distinctive, perh aps pathognomonic, chondromyxoid-like matrix often distributed in a nodular pattern. This histopathologically distinctive lesion can be seen in many r egions of the neuraxis, often with a dural association, and most commonly a long the vertebral column. It appears to be a slow-growing lesion and, with wide excision, the prognosis is excellent. The etiology remains unclear, b ut the preponderance of data favors a reactive rather than neoplastic proce ss. If this putative pseudotumor is not recognized histopathologically, a n eoplastic or infectious differential might result in inappropriate investig ations and potentially harmful therapies.