Anaplastic thyroid carcinoma producing the granulocyte colony stimulating factor (G-CSF): report of a case.

We report herein the unusual case of a 60-year-old woman with an anaplastic thyroid carcinoma which produced granulocyte colony stimulating factor (G-CSF). She presented with large neck masses, respiratory difficulty, and a high fever. Laboratory examinations revealed marked leukocytosis of 43,200/mm3 with 85% granulocytes and an elevated G-CSF level of 67 pg/dl. Total thyroidectomy with bilateral node dissection and tracheostomy was performed, and a histological diagnosis of large-cell anaplastic thyroid carcinoma was confirmed. Immunohistochemical examination with a polyclonal antibody against G-CSF stained the tumor cells. Although the respiratory difficulty, fever, and marked granulocytosis subsequently improved, she died 1 month after undergoing surgery due to metastatic mediastinal disease.