Suppurative Thyroiditis due to Nocardia in An Immunocompromised Patient

ABSTRACT Objective:Nocardia is an opportunistic organism that usually infects immunocompromised patients. However, suppurative thyroiditis is a rare complication of nocardiosis. Methods: We report a case of Nocardia thyroiditis in an immunosuppressed patient following renal transplant. Results: A 45-year-old man presented with worsening diffuse muscle pain, weakness, and subjective fever. He had a significant history of recent renal transplant with immunosuppression at the time of presentation. Mild swelling was noted in the right submandibular area, and multiple papules were noted on the skin. Although pulmonary exam revealed no abnormalities, computed tomography revealed numerous bilateral small pulmonary nodules and multiple hypodense thyroid nodules. A positron emission tomography scan showed hypermetabolic activity in the mediastinum, lungs, thyroid, and skeletal muscles. During a right-thyroid lobectomy to rule out post-transplant lymphoproliferative disease, purulent discharge from a ruptured cyst was identified. Histopathology revealed granulomatous, focally suppurative thyroiditis and filamentous microorganisms morphologically resembling Nocardia. The pathological and clinical findings in the thyroid, lungs, skin, and nervous system correlated with disseminated nocardiosis. Conclusion:Nocardia thyroiditis is a rare presentation of disseminated nocardiosis. Diagnosis in our case was achieved upon analysis of unusual purulent drainage during thyroid lobectomy for suspicion of post-transplant lymphoma. Thyroidectomy may be considered in resistant and recurrent Nocardia thyroiditis following surgical drainage and antibiotic management. Although most cases of suppurative thyroiditis are of bacterial origin, this case suggests the importance of considering Nocardia as a possible etiological agent of suppurative thyroiditis, particularly in an immunocompromised patient with additional pulmonary, cutaneous, and nervous system manifestations.