Multinodular goitre complicated by abscess due to E. coli ans_5151 948..949 Infection of the thyroid gland with subsequent abscess formation is a relatively rare condition and as such can present a diagnostic dilemma. Innate resistance of the gland to infection is well recognized, with structural abnormalities increasing predisposition to infection.
1,2A 74-year-old female presented to her general practitioner with a history of lethargy, non-productive cough and rhinorrhoea. An upper respiratory tract infection was presumed and follow up was planned without intervention. However, she presented to North-East Health Wangaratta hospital 2 days later with fever and rigors. She further reported a dull pain in the left side of her neck and felt that her known goitre had increased in size.In 1987, the patient had undergone a right subtotal thyroidectomy for a 35 mm ¥ 30 mm ¥ 25 mm thyroid lesion, for which the histopathology returned a multinodular goitre. In 1996, swelling of the left thyroid gland was noted and thyroxine prescribed. Within 4 years, the patient had begun experiencing pressure symptoms and repeat ultrasound of the left thyroid lobe revealed a multinodular goitre, with 'cold' lesions demonstrated on nuclear scanning.On general inspection, she appeared well and had a temperature of 37.5°C. Examination of the neck revealed a large, predominately left-sided goitre, which was tender and warm to palpation and lacked a bruit.Laboratory testing at admission showed a normocytic anaemia with haemoglobin 90 g/L, white cell count of 15.9 ¥ 10 ∧ 9/L, and C-reactive protein of 221.7 mg/L. Thyroid stimulating hormone had remained suppressed (<0.05 pmol/L) and free thyroid hormone was within normal limits. Serum calcium, phosphate and parathyroid hormone were unremarkable. Blood and urine samples were taken for culture yet did not yield an organism and chest X-ray was normal.Broad-spectrum antibiotic therapy and fluid resuscitation were commenced. Ultrasonography of the thyroid showed a large, complex cystic nodule in the left thyroid gland with irregular internal septations but without internal vascularity (Fig. 1). Computerized tomography confirmed the finding of a multi-loculated cystic mass, noting moderately dense fluid and significant deviation of surrounding structures including the trachea and left common carotid artery and internal jugular vein (Figs 2 and 3). A diagnosis of thyroid abscess was made after an ultrasound-guided aspirate recovered thick, turbid material showing numerous acute inflammatory cells. The patient proceeded to theatre for drainage of the loculated abscess, producing about 80 mL of pus. Escherichia coli was subsequently identified as the causative organism in two cultures. Recovery with wound packing and antibiotics was uneventful and a communicating fistula was excluded through barium swallow at a later date.The rarity of bacterial infection within the thyroid stems from a rich vascular and lymphatic flow, anatomical separation by multiple facial planes, and its high iodine concentr...