Angioinvasive Fungal Thyroidits.

Fungal thyroiditis is an uncommon cause of thyroid inflammation and infection. This condition is typically observed within immunosuppressed patients, such as those with a hematologic malignancy or those receiving corticosteroids or chemo-radiation therapies. This report describes a case of a 66-year-old male with underlying high-risk myelodysplastic syndrome who presents with complaints of fever, right anterior neck pain, severe dysphagia, dysphonia, and difficulty managing upper airway secretions. A cervical computed tomography scan was performed and depicted a lowdensity area within the right thyroid lobe, infiltration of adjacent anterior fat tissue, and a retropharyngeal fluid collection. Ultrasound-guided biopsy and cytology revealed pauci-septate fungal hyphae with vascular invasion and abundant necrosis which is consistent with a diagnosis of angioinvasive fungal thyroiditis. This case demonstrates the importance of considering fungal species as a potential etiology in immunosuppressed patients with acute development of thyroiditis.