Efficacy of fine needle aspiration cytology in the diagnosis of tuberculosis of the thyroid gland: a study of 18 cases.

Tuberculosis of the thyroid gland is an extremely rare condition. Amongst 1565 cases of thyroid lesions subjected to fine needle aspiration cytology (FNAC) over a period of nine years, 18 cases (1.15 per cent) were found to have cytological features consistent with tuberculosis thyroiditis. Acid-fast bacilli were isolated in all cases. The ages of the patients ranged from 36 to 52 years with a median age of 46 years: there were 12 females and 6 males. All the patients presented with painless solitary nodules of the thyroid. Three patients had concomitant cervical lympadenopathy and four patients were known to have tuberculosis of the lungs which was being treated. Solitary nodules of the thyroid were confirmed by a thyroid scan with radioactive iodine. Fine needle aspirates from thyroid swellings showed epithelioid granulomas with necrosis in all cases. There were no false reports or complications. It is evident from this study that FNAC is an efficient way with which to detect tuberculosis of the thyroid gland.