Atypical forms of spinal tuberculosis: case report and review of the literature

The object of this report is to highlight some of the less known atypical features of spinal tuberculosis (TB) in the hope of facilitating early diagnosis. Pure neural arch and sacral TB is rare and the co-existence of these two as widely separated skip lesions in the same patient is even rarer.

An unusual case of tuberculous process affecting the sacrum as well as the neural arches of upper cervical vertebrae is presented. Neither the clinical features nor the imaging techniques, including radiography, bone scintigraphy, computed tomography, and magnetic resonance imaging, were helpful in establishing the diagnosis. The destructive lesion of the sacrum with a rectally palpable presacral mass was thought to be a chordoma or chondrosarcoma until the patient developed upper cervical cord compression with an extradural myelographic block. Development of this second destructive lesion involving the posterior spinal elements (the neural arch) led to a diagnosis of malignant spinal metastasis. The true diagnosis was only revealed by the histology of the solid tumor-like extradural mass in the upper cervical region and demonstration of acid-fast bacilli (AFB) in the lesion. Anti-TB chemotherapy resulted in complete resolution of sacral and cervical lesions as well as the neurologic deficits.

Differential diagnosis of the obscure spinal lesion should include tuberculosis, specifically the atypical forms; especially because complete cure is possible with early treatment and neurologic morbidity is high in neglected cases.