Clinical diagnosis and treatment of primary thyroid tuberculosis: a retrospective study

BACKGROUND: Primary thyroid tuberculosis (PTT) is an uncommon type of extrapulmonary tuberculosis, which is caused by Mycobacterium tuberculosis. It does not have specific clinical manifestations, and most cases are diagnosed through postoperative histopathological examination. OBJECTIVE: To evaluate the diagnostic pattern and management strategy among patients with primary thyroid tuberculosis. DESIGN AND SETTING: Retrospective study on patients with primary thyroid tuberculosis in the First Hospital of Jilin University (Changchun, China). METHODS: Between March 2015 and June 2020, nine cases of PTT were diagnosed and treated in the Department of Thyroid Surgery of the First Hospital of Jilin University. Age at diagnosis, primary symptoms, preoperative biopsy, operation method, pathological classification, acid-fast staining test, anti-TB therapy and prognosis were registered in order to explore the appropriate protocol for diagnosis and treatment of this disease. RESULTS: None of the patients was diagnosed with thyroid tuberculosis before surgery. All the patients underwent surgery. Granulomatous changes or caseous necrosis in thyroid tissue were found through postoperative histopathological evaluation. Polymerase chain reaction (PCR) results for Mycobacterium tuberculosis were positive in all patients. Most patients had a good prognosis after surgery and anti-tuberculosis drug therapy. CONCLUSION: PTT is a rare disease. It is important to improve the preoperative diagnosis. Preoperative diagnostic accuracy relies on increased awareness of the disease and appropriate use of preoperative diagnostic methods, such as PCR detection, fine-needle aspiration cytology, acid-fast bacillus culture, ultrasound and blood sedimentation. PCR detection of M. tuberculosis is recommended as the gold standard for diagnosis.