Abstract
Langerhans cell histiocytosis (LCH) is a rare disease involving monoclonal proliferation of Langerhans cells. The disease can affect every organ in the whole body. This time we report an extremely rare case of LCH affecting the thyroid which was detected by PET-CT scanning. In this case, we had great difficulties in differentiating the disease from thyroid cancer with bone metastasis, and surgery for the purposes of diagnosis and treatment offered the histopathological diagnosis of LCH. After the operation the patient has been treated by chemotherapy. Long-term follow-up would be mandatory for the patient by keeping possible occurrence of late effect or secondary cancer in mind. PET-CT also appears to be beneficial for diagnosis of recurrence or secondary cancer.
