Sacral tuberculosis: a case report and review of the literature

BACKGROUND: We present a patient with a heterogeneously enhancing lesion within the body of the sacrum and the sacral canal. Sacral tuberculosis (TB) was suspected because of a history of familial exposure. Few cases isolated to the sacrum have been reported in the literature. The characteristic histopathologic and magnetic resonance imaging (MRI) findings are also presented. CASE DESCRIPTION: A 31-year-old African-American male presented with an 8-month history of lower back pain radiating into his legs as well as numbness and weakness of the right foot. His history revealed PPD conversion following an exposure to active pulmonary TB 3 years prior for which he received 6 months of isoniazid prophylaxis. An MRI scan revealed a large heterogeneously enhancing lesion involving the sacrum with extension into the sacral canal. The patient underwent computed tomography (CT)- guided needle biopsy of the sacral lesion. Cytopathologic examination revealed caseating granulomas. Acid-fast bacilli cultures were positive for Mycobacterium tuberculosis. He was placed on a 6-month course of isoniazid, rifampin, pyrazinamide, and ethambutol. At 3-month follow-up, his examination and symptoms had improved. CONCLUSIONS: Sacral TB is an extremely rare cause of lower back pain with radiation into the lower extremities. TB should always be considered in the differential diagnosis of isolated sacral masses, especially in light of today's increasing multidrug resistance and immunosuppressed population.