Spontaneous thyroid abscesses without underlying malignancy: a differential diagnosis for recent onset or rapidly growing thyroid masses

Thyroid abscess is a rare cause of neck swelling in patients. The rich iodine environment, good vasculature and protective capsule make bacterial growth suboptimal. We present two cases of thyroid abscess without underlying thyroid cancer in immunocompromised patients presenting to a thyroid unit. The demographics, clinical details, investigation, management and outcomes of two patients with thyroid abscess were reviewed. Two octogenarian women were referred with neck lumps originating in the thyroid gland. Ultrasound demonstrated fluid collection in the thyroid, aspiration of which demonstrated Escherichia coli. The patients had underlying diabetes mellitus and raised inflammatory markers at presentation. Both were treated with antibiotics and follow-up demonstrated complete resolution of infection with no underlying thyroid neoplasm. Thyroid abscesses are an important differential diagnosis in rapidly growing thyroid masses due to the potential for rapid deterioration, especially in patients with conditions or medications causing immunosuppression. Urgent admission should be considered to facilitate prompt intervention and rapid recovery.