Pathological fracture of the atlas secondary to plasmacytoma.

Plasmacytoma of the atlas with pathological fracture has not been previously reported. A 72-year-old man was admitted to our clinic with a 5-month history of occipital headache. Neurologic examination revealed mild occipital neuralgia, difficulty with movements of the cranium, hyperactive deep tendon reflexes, but no Babinski sign. Magnetic resonance imaging (MRI) of the cervical spine showed a 1x2 cm well-circumscribed extradural mass, with lytic destruction and fracture of the lateral mass of C1. Preoperatively dynamic cervical radiographs showed no instability. Using a transcondylar approach, the tumor was removed, and posterolateral fixation and fusion (using iliac autograft) was performed. Biopsy was reported as plasmacytoma. The patient was pain-free with bony fusion 3 years after surgery. This paper presents a pathologic fracture of C1. Although the primary treatment of plasmacytoma is non-surgical, the need for tissue diagnosis in relevant areas may dictate an open biopsy procedure. Such cases may require a decompression and reconstruction procedure.