Granulocyte colony-stimulating factor and IL-6 producing carcinosarcoma of the esophagus manifesting as leukocytosis and pyrexia: a case report

Some patients with nonhematopoietic tumors show leukocytosis and pyrexia without overt inflammation. This report describes the case of a 47-year-old Japanese man who complained of persistent fever. Hematological examination showed marked leukocytosis with neutrophilia and elevation of C-reactive protein (CRP). Esophagogastroduodenoscopy demonstrated a polypoid tumor (5 cm in length) in the thoracic esophagus, which was suggested to cause high fever. After subtotal esophagectomy, leukocyte count and CRP level rapidly decreased and the high fever disappeared. Histological examination revealed a carcinosarcoma with four components: squamous cell carcinoma (SCC), basaloid carcinoma, spindle/pleomorphic cell sarcoma, and osteosarcoma. Immunohistochemically, the spindle/pleomorphic cells were positive for granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6). The patient was alive without recurrence 16 months after surgery.