Syphilitic meningomyelitis misdiagnosed as spinal cord tumor: Case and review.

Context: Syphilitic meningomyelitis is a rare manifestation of neurosyphilis, not well described in the literature. Methods: We reported a rare case of a 29-year-old female with syphilitic meningomyelitis. Her clinical manifestations and imaging findings were discussed with the related literatures reviewed. Results: The patient presented with progressive bilateral lower extremities numbness and weakness for months. Laboratory tests revealed positive serum Treponema pallidum Hemagglutinin Test (TPHA) and rapid plasma reagin test (RPR). The cerebral spinal fluid (CSF) was positive with TPHA but negative for RPR with lymphocytic pleocytosis and elevated protein. Spinal MRI showed swelling and high-signal intensity of thoracic spinal cord except T6-7 level with associated gadolinium enhancement ("flip-flop sign") and peripheral strip-like enhancement on T1WI ("candle guttering appearance"). She was initially diagnosed as spinal cord tumor due to the chronic clinical onset and cord swelling with central enhancement found on thoracic MRI. After dramatic clinical and radiographic improvement with dexamethosone and serological tests of syphilis, she was diagnosed as probable syphilitic meningomyelitis. Till now, there are 12 cases of syphilitic myelitis reported with spinal cord MR images. Thoracic cord is the predominant involved segment (10/12), "candle guttering appearance" is the most common enhancing characteristics of the lesion (7/12), "flip-flop sign" may be seen in the stage with significant inflammation (3/12). Conclusion: Syphilitic meningomyelitis can occur at early or late stage of syphilis, the onset may be acute, subacute or chronic. The imaging findings suggested focal inflammation of the spinal cord. Prognosis is relatively good after proper treatment.