Vertebral Instability Syndrome as the Initial Manifestation of Advanced Tuberculosis in an Immunocompetent Patient: A Case Report

<i>Introduction</i><i>:</i> The inability of the spine to perform movements in the absence of pain or neurological manifestations is related to the term instability. Currently, rigorous records of endemic infectious diseases are scarce in our region, as are data on vertebral neoplasms; therefore, the diagnostic approach is complex. In 2025, 11 patients with tuberculosis were evaluated at the University Hospital of the Andes - Merida, Venezuela. It is known that the main risk factors for developing this disease are related to malnutrition and immunodeficiency. Clinically, the diagnostic considerations for tuberculosis include the typical aspects of a bacterial infection, and when vertebral lesions are present, neoplastic space-occupying lesions are considered more frequent. Likewise, in rare cases where there are no risk factors for the development of any type of infection, the diagnosis often goes unnoticed. <i>Case presentation:</i> We present the case of a 44-year-old male patient, currently incarcerated, who presented with a four-month history of progressive back pain. He subsequently developed paresthesia, decreased sensation and motor function beginning in the T4 dermatome, impaired bowel and bladder control, and paraparesis with hyperreflexia. An imaging study performed five months after the onset of symptoms revealed an extensive retropleural space-occupying lesion extending from T3 to T12. Due to the established chronic neurological deficit, two possible approaches were considered: percutaneous biopsy versus thoracotomy. A right posterolateral thoracotomy between the 5th and 6th ribs was chosen, with the participation of thoracic surgery and neurosurgery teams. Excision of approximately 250 grams of a yellowish, granular, Caseo-type mass was achieved, and a biopsy of the granuloma was taken. A chest tube was left in place and there were no post-operative complications. <i>Results:</i> The caseous material analysis showed: absence of acid-fast bacilli or bacterial morphology, presence of -3 leukocytes/field, no fungal elements were observed on KOH, and the culture was negative at 48 hours. The granulomatous tissue biopsy showed: chronic “caseating” (necrotizing) inflammation consistent with tuberculous etiology. The postoperative course was satisfactory with a decrease in pain within 24 hours. Pharmacological treatment was initiated with rifampicin, isoniazid, and ethambutol, with excellent results; absence of pain, although dystonia persisted in the lower extremities with paraparesis. <i>Conclusions:</i> It can be concluded that the diagnostic approach to vertebral tuberculosis in immunocompetent patients is complex, as it is a rare entity; however, a high clinical suspicion with appropriate selection of diagnostic methods can be useful.