Primary tuberculosis of the thyroid gland complicated with abscess: Case report

Introduction and importance Tuberculosis (TB), caused by Mycobacterium tuberculosis , mainly affects the lungs and lymph nodes but rarely involves the thyroid. Thyroid TB is usually secondary to infection elsewhere, while primary thyroid TB, where the thyroid is the initial site, is extremely rare and more common in patients with preexisting thyroid disease. Its nonspecific presentation often delays diagnosis and treatment. This case highlights the need for a high index of suspicion for early detection and management. Case presentation A 40-year-old female farmer presented with a 20-year history of anterior neck swelling, which increased in size over two months. She developed pain, bilateral cervical lymphadenopathy, and low-grade fever. Examination revealed a sinus tract with purulent discharge from the right thyroid lobe and multiple cervical lymph nodes. Ultrasound suggested thyroid TB; CT scan suggested thyroid cancer with nodal metastasis. Fine needle aspiration cytology confirmed TB. Right thyroid lobectomy with left subtotal thyroidectomy was performed, and histopathology confirmed thyroid tuberculosis. She was treated with first-line anti-TB medications and followed for six months, showing full improvement. Conclusion Primary thyroid TB is exceptionally rare and can mimic malignancy. FNAC and biopsy can confirm TB by demonstrating granulomatous inflammation with caseation and identifying Mycobacterium tuberculosis . Clinicians should consider TB in thyroid lesions, particularly in endemic areas, to ensure timely diagnosis and appropriate treatment.