Thyroid Langerhans cell histiocytosis and papillary thyroid carcinoma.

A 27-year-old female, married with two children, presented to our clinic with a 1-year history of thyroid swelling and pressure symptoms on lying backward and bilateral cervical lymphadenopathy. The patient was a known case of panhypopituitarism for 5 years. Comprehensive patient evaluation including FNAC with papillary thyroid cancer result then she underwent total thyroidectomy and bilateral neck dissection and final histologic examination confirmed papillary thyroid carcinoma in the background of lymphocytic thyroiditis, associated with Langerhans cell histiocytosis (LCH). The draining cervical lymph nodes were also involved by LCH and metastatic papillary thyroid carcinoma. Although the association of LCH with papillary thyroid carcinoma in the thyroid has been reported, their co-existence with LCH in the draining lymph nodes is very uncommon.