[A case of rheumatoid arthritis complicated with pseudotumor around odontoid process successfully treated by...

A 69-year-old-female with a history of rheumatoid arthritis since 1975 had suffered from dysesthesia of extremities since October 1989. Radiating pain and weakness occurred when she tried to stand up on Dec. 25 in 1989. She was admitted to our hospital in October 1990. Physical examination showed emaciation, hypesthesia of extremities, hypesthesia over the right chest and back, impaired vibration and position sense, and hyperreflexia. Laboratory findings revealed that the erythrocyte sedimentation rate was elevated to 46mm/hr, rheumatoid factor (RF) to 83.1IU/ml and CRP to 3.7mg/dl. Her blood sugar was high and she was diagnosed as having diabetes mellitus. Cervical X ray film showed atlanto-axial subluxation. A pseudotumor around the odontoid process bulging into the spinal canal and compression of the upper cervical cord was observed by MRI. In spite of administration of bucillamine (100mg/day), the size of pseudotumor did not change. Methotrexate (MTX) at a dose of 5mg/week was started in February 1991 and the pseudotumor decreased in size with a concurrent reduction of ESR, RF and CRP. However, the high intensity lesion by T2 weighed image did not change and dysesthesia persisted. The pseudotumor was thought to be due to pannus and it was revealed that MTX was effective for reduction. The persistent dysesthesia was probably due to the degeneration of the upper cervical cord, although diabetic neuropathy may also have played a role.