Ultrasound of Thyroid Langerhans Cell Histiocytosis with Papillary Thyroid Carcinoma: A Report of Two Cases and Literature Review

Langerhans cell histiocytosis (LCH) is an uncommon disease of unknown etiology, which involves mainly in the bone and skin and rarely the thyroid. Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. However, thyroid LCH complicated with PTC is rarer. Awareness of sonographic feature is helpful for clinical managment, especially prior to the surgery. Here, we report two patients who have histologically confirmed thyroid LCH complicated with PTC and summarize these cases with sonographic features including enlargement of the thyroid, multiple hypoechoic nodules with microcalcifications as well as enlarged cervical lymph nodes. The relvent literatures will be reviewed and discussed.