Tuberculosis - Erler Zimmer
Clinical History
A 37-year-old female presents with escalating thoracic back pain, having a history of untreated human immunodeficiency virus (HIV) infection and pulmonary tuberculosis. She reports ongoing low-grade fevers, chills, and weight loss. Examination reveals a cachexic patient with tender thoracic vertebrae at multiple levels. Blood tests indicate elevated serum calcium and erythrocyte sedimentation rate. An X-ray of her spine reveals lytic areas in the thoracic vertebrae. During hospitalization, she develops urosepsis and succumbs.
Pathology
The specimen consists of a portion of the patient’s thoracic vertebral column, sawn longitudinally and mounted to display the cut surface of seven thoracic vertebrae. All vertebrae exhibit osteolytic areas, ranging from 1 to 12 mm in diameter, containing caseous degenerative material (mostly lost) and surrounded by a thin zone of dense bone. The tuberculous inflammatory process extends into one intervertebral disc and spreads outside the vertebral bodies, forming collections of caseous material beneath the anterior longitudinal ligament. This is an example of tuberculous mycobacterial osteomyelitis of the vertebral column with paravertebral extension, known as Pott’s Disease.
Further Information
Tuberculosis (TB) is a chronic pulmonary and systemic infectious disease caused by Mycobacteria tuberculosis. Transmission occurs primarily through inhalation of aerosolized droplets of M. tuberculosis. Risk factors include residence in a 'developing' country, immunosuppression (e.g. HIV, steroid use, anti-TNF use, and diabetes), chronic lung disease (e.g. silicosis), alcoholism, and generalized malnutrition.
After initial pulmonary infection, individuals may enter an asymptomatic latent infection phase. In the immunocompromised population, primary TB may manifest as active infection. Manifestations include pulmonary symptoms and extra-pulmonary symptoms such as lymphadenopathy, meningitis, and disseminated miliary TB. Reactivation of latent TB, typically during periods of weakened immunity, leads to secondary tuberculosis with symptoms like cough, haemoptysis, fever, night sweats, and weight loss.
Osseous infection occurs in 1-3% of TB patients, with a higher incidence in developing countries and immunocompromised individuals. Pott’s disease, accounting for 40% of TB bone infections, results in destructive vertebral disc and vertebrae erosion, leading to compression fractures with symptoms of cord or nerve root compression. Diagnosis involves clinical history, chest X-ray, multiple sputum cultures, Mantoux skin tuberculin test, serum interferon-gamma release assay, and biopsies of suspected infection sites for culture.
