Calcifying pseudoneoplasm of the atlantoaxial joint in a child

Calcifying pseudoneoplasm of the spine is a rare nonneoplastic lesion of unknown origin described in adolescents and adults. Its clinical manifestations include axial pain, myelopathy, or radiculopathy. Surgery is the preferred method of treatment. The authors report the occurrence of calcifying pseudoneoplasm at the C1-2 cervical segment in a 22-month-old child who became completely asymptomatic 2 months after open biopsy. A review of the literature is presented, emphasizing the uniqueness of the presented case in comparison with the previously published cases. The 22-month-old healthy girl presented with sudden onset of neck pain. Due to persistence of the symptoms 2 weeks after onset, imaging studies were performed that revealed an inhomogeneous calcified mass extending from the transverse ligament to the C1-2 interlaminar space and facet joint on the left side. Open biopsy of the mass at the C1-2 lamina was performed. The histological features were consistent with calcifying pseudoneoplasm. The child's neck pain progressively improved and she remained asymptomatic at the 1-year follow-up. The postoperative MRI at 8 months did not reveal any progression of the lesion. Contrary to reported cases, calcifying pseudoneoplasm of the spine may occur as early as 2 years of age and should be included in the differential diagnosis of calcified lesions in this age group. Complete resection is not a prerequisite to clinical improvement when there is no compromise of neural structures; conservative management is appropriate.