Tuberculosis of thyroid gland is extremely uncommon. The incidence is low even in countries where the prevalence of tuberculosis is high [
We report three cases of primary thyroid tuberculosis.
A 21-year-old female presented with history of fever, anterior neck swelling, and weight loss of 3.5 kg for 3-4 months. The family history was significant for tuberculosis in one brother. On examination, she had marked swelling of anterior neck with no lymphadenopathy. Clinically, she was euthyroid. The systemic examination was unremarkable. Her complete blood count was normal with an ESR of 25 mm/1st hour. Mantoux test was positive. The routine biochemistry were all within the normal limits. Biochemically, she was also euthyroid. Her Technetium 99 thyroid scintigraphy revealed cold nodule in the lower aspect of right thyroid lobe.
Fine-needle aspiration cytology (FNAC) showed caseation necrosis, and pus from nodule did not show AFB, but pus culture was positive for Tubercle Bacilli. Therefore, she was started on antituberculous treatment (ATT) with four drugs regimen for first 3 months followed by 3 drugs regimen for the next 6 months. After treatment, she had complete resolution of swelling (Figures
(a) Large nodule in front of the neck (before Treatment). (b) Complete resolution of swelling after treatment.
A 51-year-old female presented with history of left thyroid lobe swelling for 3-4 years, which was gradually increasing in size with no compressive or any associated symptoms. On examination, she had a left thyroid nodule which was nontender and moving with swallowing with no palpable lymph node. The systemic examination was unremarkable, and she was clinically euthyroid. Her initial workup included FNAC of left thyroid lobe which showed follicular lesion with prominent Hurthle cell. Her Technetium 99 thyroid scintigraphy revealed cold nodule in left lobe of thyroid. Ultrasound of thyroid showed a left sided hypoechoic nodule measuring
A 32-year-old male presented with a solitary nodule over the right side of lower neck for three months with progressive enlargement. He had no systemic symptoms. On examination, there was a solitary, nontender, and firm swelling on the right side of neck with no evidence of lymphadenopathy. Systemic examination was unremarkable, and clinically, he was euthyroid. His complete blood count, ESR, and routine biochemistry were within normal limits. Biochemically, he was euthyroid. His Technetium 99 thyroid scintigraphy revealed multinodular goiter involving both lobes. Ultrasound of thyroid revealed multinodular goiter with the largest nodule (
(a) Large solitary nodule over the right lower neck before treatment. (b) Complete resolution of the swelling after anti-tuberculous treatment.
Tuberculosis of the thyroid gland is an extremely rare disease. According to the literature, the frequency of thyroid tuberculosis is 0.1%–0.4% [
Extrapulmonary tuberculosis may have different clinical manifestations and may be difficult to diagnose. In the thyroid gland, the tuberculous involvement may be in two main forms. First, which is more common, is miliary spread to the thyroid gland as a part of generalized dissemination. Less common is focal caseous tuberculosis of thyroid, presenting as a localized swelling mimicking carcinoma [
The clinical presentation is often subacute, but it may be acute in case of abscess or thyroiditis [
The thyroid tuberculosis is usually not investigated because of its rare occurrence. A past history of tuberculosis concomitant with cervical lymphadenopathy and the sites of tuberculous involvement might lead to the correct clinical diagnosis. If mycobacterial infection is suspected, a chest X-ray and a tuberculin skin test (PPD) should be performed [
The imaging techniques are not very helpful in establishing the diagnosis and have been described only sporadically due to the disease’s rare occurrence [
Thyroid tuberculosis should be differentiated from all the main diseases of the thyroid. The differential diagnosis of tuberculous thyroiditis depends on the presence or absence of local pain. If pain is the predominant clinical finding, then the differential diagnosis lies between an infectious form of thyroiditis and subacute granulomatous thyroiditis (De Quervain’s, thyroid sarcoidosis, etc.) [
Many diseases may cause granulomatous inflammation in thyroid, like granulomatous thyroiditis, palpation thyroiditis, fungal infection, tuberculosis, sarcoidosis, granulomatous vasculitis, and foreign body reaction. However, caseation necrosis is seen only in tuberculous inflammation. In the event where pain is absent, thyroid tuberculosis might be falsely diagnosed as thyroid malignancy; the two conditions may even coexist [
Initially, treatment of thyroid tuberculosis consisted of antituberculous drugs combined with surgical removal of the affected parts of the thyroid gland [
In conclusion, Thyroid tuberculosis is rare, but should be considered as differential diagnosis of thyroid masses especially in countries like Pakistan, where there is a high prevalence of tuberculosis. Past history of tuberculosis elsewhere in the body or presence of cervical lymphadenopathy and high ESR values may help in the diagnosis, but thyroid tuberculosis can occur even in the absence of these features. FNA is the main diagnostic method to diagnose the disease. The treatment is mainly based on the antituberculous agents, but surgery or drainage may be required for large abscess along with antituberculous drug therapy.