Intraosseous Calcifying Pseudotumor of the Axis: A Case Report

Study Design. A case report and review of the literature. Objective. To present the first case of intraosseous calcifying pseudotumor arising from the axis. Summary of Background Data. Calcifying pseudotumor is a very rare disease. Only 24 cases have been previously reported. Methods. A case of calcifying pseudotumor involving the body, dens, and laminae of the axis in a 60-year-old male patient was managed with total laminectomy of the axis and instrumented occipitocervical fusion, followed by the curettage of the body and dens of the axis and autogenous iliac bone graft. Medical records, imaging studies, microscopic findings, and related literature are reviewed. Results. Microscopic examination showed amorphous, basophilic, and chondroid calcifying masses surrounded with palisading histiocytes and foreign body-type giant cells. The findings were consistent with those of calcifying pseudotumors previously reported in other sites of the body. At 24 months after operation, a significant reduction of neck pain was achieved. But there was evidence of local recurrence of the lesion in the body and dens of the axis with a local progression of the preexisting lesion in the facet joints. Conclusion. This is the first report of intraosseous calcifying pseudotumor arising from the axis.