TB infection of the spine classically presents as Pott disease. Other presentations include tuberculous arachnoiditis, nonosseous spinal tuberculoma, and spinal meningitis. In North America, Cascino and Dibble provided one of the first descriptions of a patient with intradural TB that developed after medical treatment had been initiated7. Histology showed ‘‘areas of necrosis surrounded by granulomatous tissue’’; however, acidfast staining and intraoperative cultures were negative. From 1980 to 2005, only twenty-two cases of intradural extramedullary TB were reported throughout the world6 . All of these cases were from outside North America, primarily in young HIV-negative patients. To the best of our knowledge, there has only been one previously reported case of intradural extrameduallary TB in an HIV-negative patient in North America in the last thirty years4 . Among adult patients with intradural extramedullary TB, there appear to be three variants1 : healthy patients with no prior history of primary TB2 , patients with disseminated TB elsewhere in the body3 , and patients with a recent history of TB that had been treated successfully with medical therapy. In the first group, acid-fast staining and operative cultures were positive and strongly suggestive of the disease.
In our review, there have only been three case reports in this group of patients with no history of primary TB2,4,8. The group with disseminated TB is the largest, and it may include HIVpositive patients on retroviral therapy3,4. In contrast, patients in the group with a recent history of TB paradoxically developed intradural pathology only after the initiation of antiTB medications3,4,6,9,11. Luo et al. reported a case of intradural TB in a healthy HIV-negative patient with no known primary infection and no risk factors for exposure12. Similarly, Compton and Dorsch described an intradural tuberculoma in the cervical spine of a healthy HIV-negative man after a trivial car accident8 . The patient had no history of TB, but both parents had pulmonary TB. For both of these cases, histology revealed a granulomatous inflammatory mass. Acid-fast staining and intraoperative cultures were positive4,8. Similarly, Mirzai reported intradural TB in a young healthy patient with no prior history of pulmonary Fig. 4 Intraoperative photograph showing the residual clumping of nerve roots in the cauda equina after the compressive mass was removed.
4 JBJS CASE CONNECTOR VOLUME 3 d NUMBER 4 d OCTOBER 23, 2013 INTRADURAL EXTRAMEDULLARY SPINAL TUBERCULOSIS EIGHT YEARS AFTER TREAT ING THE PRIMARY INFECTION
Downloaded From: http://caseconnector.jbjs.org/ by a Thomas Jefferson University User on 01/20/2014 TB4 .
In this case, histology was suggestive of TB; however, acidfast staining and intraoperative cultures were negative. Among cases with a known history of pulmonary TB, O’Hickey et al. reported the formation of a spinal tuberculoma fifteen months after successful treatment of the pulmonary disease13. Similarly, Shim et al. described a patient with intradural TB that developed only five weeks after initiation of medical treatment14. For both cases, acid-fast stains and cultures were negative but histology confirmed a granulomatous inflammatory mass. In a review of twenty-five case reports by Roca, the formation of an intradural extramedullary mass paradoxically took place after the initiation of anti-TB medications in young healthy HIV-negative patients9 . In almost all cases of intradural TB, acid-fast staining and cultures from surgical specimens are negative while histology is suggestive. The mechanism is poorly understood; however, aberrant interplay between the bacteria and the host’s immune system may be the cause4,6. Tuberculomas may also represent a granulomatous healing response rather than a true bacteriologic reactivation9 . Our patient developed lower-extremity weakness and pain caused by the formation of an intradural extramedullary tuberculoma. The insidious nature of the presentation, negative microbial studies, and granulomatous histology were suggestive of an intradural extramedullary tuberculoma.
However, the eight-year delay between the pulmonary disease and subsequent spinal pathology was atypical, and this type of delayed presentation has not been previously reported. To our knowledge, he is also the oldest reported patient to develop an intradural extramedullary tuberculoma, and we believe that this is only the second reported case of an intradural tuberculoma in a healthy patient from North America. This combination represented a diagnostic challenge for both the orthopaedic surgeons and the neurosurgeons. Patients with a history of TB and an intradural mass on MRI should be offered a biopsy or surgical decompression if neurologic symptoms are present. Postoperatively, granulomatous pathology with or without positive cultures is suggestive of intradural TB. Anti-TB treatment for a minimum of six to nine months is appropriate. Typically, treatment for nine months is given to patients with a recent history of TB, concomitant bone disease, or culture-positive serology. Serial MRI imaging with a minimum of two years of clinical follow-up is suggested.
Kushagra Verma, MD
Alexander Vaccaro, MD, PhD
Joshua Heller, MD Departments of Orthopaedic Surgery (K.V., A.V.) and Neurosurgery (J.H.),
Thomas Jefferson University Hospital, 834 Chestnut Street #1432, Philadelphia, PA 19107. E-mail address for K. Verma: email@example.com Tracey Crothers, MD University of Southern California, 1200 North State Street, GNH 3900, Los Angeles, CA 90033 Brian Neuman, MD Washington University School of Medicine, Campus Box 8233, 660 South Euclid Avenue, Saint Louis, MO 63110