A18.81

Clinical Causes: Infection with *Mycobacterium tuberculosis*, typically through the bloodstream or lymphatic system from a primary TB site. Reactivation of latent tuberculosis bacteria within the thyroid gland. Spread from adjacent neck tissues or lymph nodes infected with tuberculosis. Rarely, via direct inoculation or hematogenous dissemination in immunocompromised individuals.

Key Symptoms: Persistent swelling or a noticeable lump in the neck region. Pain or tenderness in the thyroid area. Possible signs of hyperthyroidism or hypothyroidism, such as weight changes, fatigue, or temperature sensitivity. Unexplained fever or night sweats. General symptoms like malaise, weakness, or weight loss.

Diagnosis Path: Diagnosing tuberculosis of the thyroid gland involves a combination of clinical evaluation and specific tests. Imaging studies such as ultrasound may reveal abnormal thyroid tissue. Fine needle aspiration biopsy (FNAB) can help collect tissue samples for microscopic examination, culture, and molecular testing to identify *Mycobacterium tuberculosis*. Blood tests including tuberculosis skin tests (Mantoux test) or interferon-gamma release assays (IGRAs) may support the diagnosis. In some cases, surgery might be necessary if the lesion is large or not responding to initial treatments.

Treatment Protocols: Treatment typically involves a prolonged course of anti-tubercular medications following standard tuberculosis protocols. The common medications include isoniazid, rifampicin, ethambutol, and pyrazinamide. The duration of therapy may extend for 6 to 12 months, depending on the response to treatment. In certain cases, surgical removal of affected thyroid tissue might be necessary, especially if there is significant damage, abscess formation, or suspicion of malignancy. Careful follow-up is essential to monitor response and prevent recurrence.