A rare case of primary tuberculosis in a solitary thyroid nodule

Abstract

Tuberculosis (TB) of the thyroid gland is extremely rare with fewer than 200 cases reported worldwide. We report a case of primary TB of the thyroid in a 73-year-old gentleman with no risk factors for TB, presenting with a painless right neck mass of one week's duration. A pre-operative ultrasound scan reported a solid-cystic, right TIRADS 5 nodule, and initial fine needle cytology showed granulomatous inflammation and was negative for AFB on Ziehl-Neelsen stain. A right hemithyroidectomy was done subsequently, and histology demonstrated necrotizing granulomatous inflammation, but TB-PCR detected Mycobacterium DNA.Primary TB of the thyroid is rare and can manifest in patients with no apparent risk factors for TB. Initial cytology may only yield granulomatous inflammation and surgery is needed to ascertain the exact cause of granulomatous inflammation and additional TB-PCR can help clinch the diagnosis.