# Unmasking primary thyroid tuberculosis - A rare but deceptive diagnosis: A case report with review of literature

## TL;DR

This case report highlights the rare and challenging diagnosis of primary thyroid tuberculosis, emphasizing the importance of considering it to avoid unnecessary treatments.

## Contribution

The paper presents a rare case of primary thyroid tuberculosis and reviews literature to emphasize diagnostic challenges and management strategies.

## Key findings

- Thyroid tuberculosis is rare, occurring in 0.1-0.4% of all thyroid diseases.
- Clinical signs are nonspecific, leading to potential misdiagnosis as malignancy or other benign conditions.
- Fine-needle aspiration cytology is effective for diagnosis, and anti-tuberculosis treatment is typically sufficient.

## Abstract

Thyroid tuberculosis is a rare condition, even in regions where tuberculosis (TB) is more common, possibly due to the thyroid gland's relative immunity. Diagnosing thyroid TB can be challenging as the clinical signs are often nonspecific.

A 75-year-old male presented with a swelling in the midline of the neck with an abscess in the lower portion of the swelling. Thyroid function tests were normal, and the tuberculin skin test returned positive. USG of the neck showed heterogeneous hypoechoic collection in the left lobe of thyroid, with surrounding inflammation and multiple subcentimetric lymph nodes in right upper, mid and lower jugular region showing necrosis. FNA revealed mixed inflammatory infiltrate predominantly neutrophils with lympho-histiocytic clusters in necrotic background. No signs of tuberculosis were detected in other organs. Based on these findings, primary thyroid tuberculosis was diagnosed. The patient was started on anti tubercular treatment resulting in a favorable clinical outcome.

TB rarely presents as a thyroid mass. A history of prior tuberculosis, the presence of cervical lymphadenopathy, and an elevated erythrocyte sedimentation rate (ESR) can support the diagnosis. Fine-needle aspiration cytology (FNAC) is an effective diagnostic method.

Although rare, tuberculosis of the thyroid must be considered before deciding on a surgical management for disorders of the thyroid. Treatment typically involves anti-tuberculosis medications, but drainage may be needed for large abscesses, and thyroidectomy might be required if the FNAC results are inconclusive.

•Thyroid tuberculosis is a rare condition(0.1-0.4% of all thyroid diseases)•The clinical manifestations of thyroid TB can vary significantly•Due to the potential for misdiagnosis as a malignancy or other benign conditions, maintaining a high index of suspicion is essential to avoid unnecessary treatments•Treatment typically involves anti-tuberculosis medications, while surgery is reserved for cases requiring drainage of large thyroid abscesses or partial thyroidectomy for significant gland involvement.

Thyroid tuberculosis is a rare condition(0.1-0.4% of all thyroid diseases)

The clinical manifestations of thyroid TB can vary significantly

Due to the potential for misdiagnosis as a malignancy or other benign conditions, maintaining a high index of suspicion is essential to avoid unnecessary treatments

Treatment typically involves anti-tuberculosis medications, while surgery is reserved for cases requiring drainage of large thyroid abscesses or partial thyroidectomy for significant gland involvement.