Langerhans cell histiocytosis of the lung and thyroid, co-existing with papillary thyroid cancer.

A 24-year-old man presented to our center with a huge goiter compressing his airway. He had a previous diagnosis of Langerhans cell histiocytosis (LCH) of the lung. Core needle biopsy was consistent with histiocytosis. Thyroidectomy was performed. A very invasive mass was encountered at the time of surgery. Histopathology result was consistent with an invasive papillary cancer of thyroid co-occurring with LCH. Although association of LCH with different malignancies has been reported, co-existing invasive papillary thyroid cancer and LCH is a rare combination.