Langerhans cell histiocytosis of the thyroid diagnosed by fine needle aspiration cytology. A case report

BACKGROUND: Langerhans cell histiocytosis rarely involves the thyroid gland even in patients with multifocal disease. Unifocal disease apparently confined to the thyroid is even more rare. CASE: A 30-year-old woman presented with a 6-cm mass in the right and a 3-cm mass in the left lobe of the thyroid. Fine needle aspiration cytology showed isolated, loose aggregates and histiocytelike cells with grooved or contorted nuclei mixed in varying proportions with many mature eosinophils, scattered and small lymphocytes, multinucleated giant cells and foamy histiocytes. CONCLUSION: The cytologic features of Langerhans cell histiocytosis are characteristic. A fine needle aspiration cytology diagnosis is confirmed by histopathologic studies, imunohistochemical staining and ultrastructural studies.