Endocrine Abstracts

Introduction: Thyroid abscess is a rare pathology, with the incidence of less than 1% of all thyroid diseases. We describe a unique case of thyroid abscess complicating post-covid-19 thyroiditis, which is the first case reported in Morocco to our knowledge.

Case presentation: A 39-year-old man who had recently recovered from a mild episode of COVID-19 infection, consulted for weight loss, palpitations and neck pain. Examination of the neck revealed enlarged, firm, and tender thyroid gland. His electrocardiography revealed sinus tachycardia. Laboratory tests showed elevated erythrocyte sedimentation rate at 40 mm/h and c-reactive protein at 75 mg/l. TSH was low (<0.05 mU/l), T4 and T3 levels were elevated at 7.72 ng/dl (reference 0.77-2.02) and 11.23 pg/ml (reference 2.2-4.6), respectively. Thyroid peroxidase antibody and TSH-receptor antibody were negative. Ultrasound of the neck showed heterogeneous goiter with areas of thyroiditis, and reduced blood flow on Doppler study. The diagnosis of subacute thyroiditis was made, and the patient was discharged home on oral prednisone (60 mg) and atenolol (40 mg) daily. During the follow-up, the prednisone was gradually tapered off over 7 weeks, and atenolol was discontinued. The thyroid function tests returned to normal at 9 weeks follow up, however the patient developed a cervical swelling with pus discharge. Ultrasonography was consistent with Thyroid abscess. A retroviral screening for Human Immunodeficiency Virus was negative. Culture of the pus from the abscess obtained during the fine needle aspiration grew Staphylococcus aureus. The patient was successfully treated with percutaneous drainage and oral amoxicillin clavulanate.

Discussion: Thyroid abscess is a less seen diagnosis, mostly so as the gland is inherently protected. The encapsulation, rich blood and lymphatic supply, and iodine content inside offer the gland protection from being seeded. Thyroid abscess usually occurs in patients who are immuno-compromised, those with pre-existent thyroid pathologies or anatomic gland anomalies. Some authors have related thyroid abscess to neoplastic causes, thyroid nodule, subacute thyroiditis, Hashimoto’s thyroiditis or traumatic causes. In our case, when no immunosuppression or anatomical factors are present, there was sufficient clinical and biological evidence within reasonable limits that failed to yield any other risk factor for thyroid abscess other than subacute thyroiditis that the patient developed after SARS-COV-2 infection.

Conclusion: Thyroid abscess is an unusual complication of post-COVID-19 subacute thyroiditis and can lead to significant morbidity. Therefore, clinicians must be aware of the presenting features and therapeutic options.