Granulomatous Thyroiditis: A Case Report and Literature Review

Abstract

Background: Granulomatous disease in the thyroid gland has been linked to viral, bacterial and autoimmune etiologies. The most common granulomatous disease of the thyroid is subacute granulomatous thyroiditis, which is presumed to have a viral or post-viral inflammatory cause. Bacterial etiologies include tuberculosis, actinomycosis, and nocardiosis, but are extremely rare. Disseminated actinomycosis and nocardiosis more commonly affect organ-transplant patients with the highest susceptibility within the first year after transplant surgery.

Case: A 45-year-old African American male, who received his third kidney transplant for renal failure secondary to Alport Syndrome, presented with numerous subcutaneous nodules and diffuse muscle pain in the neck. Further workup revealed bilateral nodularity of the thyroid. Fine needle aspiration of these nodules demonstrated suppurative granulomatous thyroiditis. Subsequent right thyroid lobectomy showed granulomatous thyroiditis with filamentous micro-organisms, morphologically resembling Nocardia or Actinomyces.

Conclusion: Disseminated granulomatous disease presenting in the thyroid is very rare, and typically afflicts immune-compromised patients. The overall clinical, cytologic and histologic picture of this patient strongly points to an infectious etiology, likely Nocardia, in the setting of recent organ transplantation within the last year.

Keywords: Fine Needle Aspiration; Granuloma; Nocardia; Thyroid.